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1
Hering, Nils [Verfasser]. "Elektrophysiologische Charakterisierung der Ionenkanäle TRPV1, TRPV3 und TRPV4 exprimiert in Xenopus Oozyten. / Nils Hering." Kiel : Universitätsbibliothek Kiel, 2016. http://d-nb.info/1096220881/34.
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Hasan, S. M. Raquibul. "Modulation of the TRPA1 and TRPV1 ion channels." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708079.
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Hellwig, Nicole. "Protonenleitfähigkeit von TRPV1 und Multimerisierung von TRPV-Kanaluntereinheiten." [S.l.] : [s.n.], 2005. http://www.diss.fu-berlin.de/2005/177/index.html.
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Sinha, Sayantani. "Role of TRPA1 and TRPV1 in Propofol Induced Vasodilation." Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618926.
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Aims: Propofol, clinically named as Diprivan is an intravenous anesthetic known to cause hypotension in patients presenting for surgery. We have investigated the vasodilatory signaling cascade by which propofol causes hypotension using both in vivo and in vitro experimental approaches.
Methods and Results: Using high-fidelity microtip transducer catheter, mean arterial blood pressure (MAP) was measured in control, transient receptor potential ankyrin subtype 1 knock-out (TRPA1-/-), transient receptor potential vanilloid 1 knock-out (TRPV1-/-) and TRPA1-TRPV1 double-knockout mice (TRPAV-/-) in the presence and absence of L-NAME (an endothelial nitric oxide synthase inhibitor) and penitrem A [a big-conductance calcium gated (BKCa) channel inhibitor]. To further support our in-vivo data, murine coronary microvessels were isolated and cannulated for vasoreactivity studies. Furthermore, NO production from endothelial cells isolated from mouse aorta was also measured and immunocytochemical (ICC) studies were performed to show the intracellular localization of TRPA1 and TRPV1. Our in-vivo data shows that the characteristic propofol-induced depressor response is dependent on TRPA1-NO-BKCa pathway. Interestingly, vasoreactivity studies in isolated murine left anterior ascending (LAD) arteries demonstrate that TRPA1 and TRPV1 communicate with each other and propofol-induced vasodilation is dependent on both TRPA1 and TRPV1. Moreover our data also suggest that NO production and BK channel activation are the downstream mediators in this pathway. Finally, we demonstrate that NO production is attenuated in primary endothelial cells isolated from TRPAV-/- mice. ICC data also shows the co-localization of these channels in mouse aortic endothelial cells.
Conclusions: This is the first study which has shown that propofol-induced vasodilation involves TRPA1 in-vivo and also there is an implication of cross-talk between TRPA1 and TRPV1 in the coronary bed. Furthermore by understanding the mechanisms by which this anesthetic causes hypotension and coronary dilation will help to mitigate the potential harmful side-effects of anesthesia in patients with little cardiovascular reserve. This will in turn ensure a better and faster post-operative recovery in patients, especially benefiting those suffering from diabetes and other cardiovascular disorders.
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SINHA, SAYANTANI. "Role of TRPA1 and TRPV1 in Propofol Induced Vasodilation." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1384901930.
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Sprague, Jared Michael. "TRPV1 Sensitization in Primary Sensory Neurons." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11441.
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Pain is a major personal and community burden throughout the world with currently limited treatment options for persistent pain due to unacceptable side effects, dependence or frank inefficacy. It is necessary to understand the anatomical and molecular pathways leading to pain to better cope with the current challenge of treating it.
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O'Leary, Caitriona. "The role of TRPV1 and TRPV4 channels in retinal angiogenesis." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709849.
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Abnormal angiogenesis is a key pathological process associated with many diseases such as metastatic cancer, atherosclerosis, and sight-threatening disorders including proliferative diabetic retinopathy, neovascular age-related macular degeneration, and retinopathy of prematurity. Calcium signalling is fundamental for many endothelial functions including the regulation of blood vessel tone, barrier selectivity and angiogenesis. Calcium influx has been implicated in retinal endothelial cell angiogenic response, but the molecular identity of the underlying calcium channels remains to be fully elucidated. In the present study we have investigated the role of the calcium permeable channels TRPV1 and TRPV4 in retinal angiogenesis both in vitro an in vivo. Both mRNA and protein expression of TRPV1 and TRPV4 were initially confirmed in RMECs using PCR and western blotting experiments, functional channel expression was confirmed using whole cell patch clamp techniques. Pharmacological inhibition of TRPV1 and TRPV4 channels reduced angiogenesis in vitro via modulation of tubulogenesis. HGF-stimulated angiogenesis was found to be sensitive to both TRPV1 and TRPV4 inhibition, but channel inhibition had no effect on VEGF or FGF stimulated angiogenesis in vitro. Inhibition of both channels in vivo reduced hypoxia-dependent retinal neovascularisation and promoted normal therapeutic angiogenesis in an oxygen-induced retinopathy mouse model. TRPV1 inhibition was found to downregulate the mRNA expression of TNF-alpha in vivo, whilst TRPV4 inhibition had no effect. TRPV1 and TRPV4 channels were also found to form functional heterotetrameric channels in retinal endothelial cells in vitro. This study provides evidence for TRPV1 and TRPV4 channels as effective therapeutic targets in retinal angiogenesis both in vitro and in vivo.
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Sinharoy, Pritam. "Cross Talk Between TRPA1 and TRPV1 Ion-Channels: Role of Nitric Oxide." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1467381679.
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Chen, Lan [Verfasser]. "Functional TRPV1 and TRPV4 channels in the murine renal vasculature / Lan Chen." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2017. http://d-nb.info/1148425926/34.
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SUGIHARA, YASUO, MINORU UEDA, HIDEYUKI NAKASHIMA, KENJIRO NAGAMINE, HISASHI HATTORI, NORIYUKI OZAKI, and KATSUNORI HIRONAKA. "INVOLVEMENT OF GLIAL ACTIVATION IN TRIGEMINAL GANGLION IN A RAT MODEL OF LOWER GINGIVAL CANCER PAIN." Nagoya University School of Medicine, 2014. http://hdl.handle.net/2237/20551.
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Fernandes, Maria Antionetta. "An investigation of the roles of TRPV1, TRPA1 and hydrogen sulfide in thermoregulation." Thesis, King's College London (University of London), 2015. http://kclpure.kcl.ac.uk/portal/en/theses/an-investigation-of-the-roles-of-trpv1-trpa1-and-hydrogen-sulfide-in-thermoregulation(811086d3-46c1-4f3f-9288-131bebf36431).html.
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The Transient Receptor Potential Vanilloid 1 (TRPV1) ion channel is an integrator of noxious stimuli, including noxious heat ( > 43°C), low pH ( < 6) and capsaicin (the pungent component of chilli peppers). Transient Receptor Potential Ankyrin 1 (TRPA1) is a closely related channel, activated by reactive oxygen species, hydrogen sulfide (H2S) and mustard oil. Their expression on primary sensory neurons is well characterised. Recent studies show that they are also expressed in non‐neuronal tissue. Whilst TRPV1 and TRPA1 antagonism is a promising analgesic and anti‐inflammatory strategy, early generation TRPV1 antagonists produced a poorly understood cross‐species side effect of hyperthermia. H2S is a vasodilator and TRPA1 activator. Inhalation of H2S can suspend animation, a state that includes a decreased body temperature. The role of TRPA1 and H2S in TRPV1‐mediated hyperthermia was investigated using TRPV1 and TRPA1 antagonists, knockout mice, H2S donors and modulators of endogenous H2S producing enzymes. The effects of TRPV1 antagonists SB366791 and JNJ17203212 and TRPA1 antagonists HC030031 and TCS5861528 on thermal and mechanical nociceptive thresholds of naïve mice were determined using the Hargreaves and automated Von Frey techniques, respectively. Antagonist‐induced changes in core body temperature of conscious, ambulatory mice were determined using radiotelemetry. Only JNJ17203212 produced a significant increase in core body temperature. The effects of the same antagonists on capsaicin‐ and mustard oil‐ induced blood flow changes in the pinna and knee were investigated, using full‐field laser Doppler perfusion. The capsaicin‐induced increase in pinna blood flow demonstrated a neuronal response; in the knee decreased flux demonstrated nonneuronal TRPV1 activation. Mustard oil similarly increased flux in the pinna and knee: TRPA1 does not exhibit any vasoconstrictor activity in this model. JNJ17203212 significantly attenuated capsaicin‐induced blood flow changes in the pinna and knee. No inhibition was observed with SB366791. HC030031 significantly reduced mustard oil‐induced blood flow increases in the pinna and knee whilst TCS5861528 had no effect. Finally, the involvement of TRPA1 blockade and H2S in JNJ17203212‐mediated hyperthermia was determined, using HC030031 and GYY4137, respectively. Whilst TRPA1 was not directly involved in our model, GYY4137 attenuated the hyperthermia elicited by JNJ17203212, suggesting H2S may have a role in TRPV1 antagonist‐mediated hyperthermia.
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Grace, Megan Stacey. "Investigating the role of TRPA1 and TRPV1 ion channels in the cough reflex." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/14571.
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Cough is under the control of sensory afferents which innervate the airways via the vagus nerve. Cough is an important protective reflex that clears the airway, but can become exacerbated and deleterious when associated with airways diseases, in which there is enhanced release of inflammatory mediators and a decrease in lung pH. These mediators sensitise airway afferents and could be driving enhanced cough associated with inflammation. Transient Receptor Potential (TRP) ion channels are associated with several disease pathologies. TRPV1 has an established role in cough, and is implicated in the aetiology of chronic cough; and TRPA1 is a promising new target. Involvement of these ion channels in the tussive reflex is awaiting comprehensive investigation. I have therefore explored the role of TRPA1 and TRPV1 in tussive responses to the endogenous irritants prostaglandin E2 (PGE2), bradykinin (BK) and low pH. To do this I have used selective antagonists and genetically modified mice in models of human, guinea pig and mouse vagal sensory nerve depolarisation; conscious guinea pig cough; and guinea pig primary ganglia cell imaging. TRPA1 and TRPV1 were shown to mediate PGE2 and BK-induced nerve depolarisation, cough, and activation of ganglia cells. In contrast, low pH-induced nerve depolarisation and ganglia cell activation was mediated via TRPV1 or Acid Sensing Ion Channels (ASICs); whereas, cough was partially attenuated with TRPA1 or TRPV1 antagonists. In summary, I have identified that TRPA1 and TRPV1 mediate PGE2 and BK-induced cough; and provided evidence that low pH-induced sensory nerve activation is mediated via TRPV1 and ASICs, but a role for TRPA1 is still unclear. These are exciting findings which add to our understanding of the mechanisms that drive the cough reflex in the healthy state; builds a base for investigating cough hypersensitivity in disease; and could help to guide the development of novel efficacious anti-tussive therapies.
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Colton, Craig K. "TRPV3 is a polymodal receptor." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1164046830.
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EL, Andaloussi-Lilja Johanna. "Activation and regulation of TRPV1 : studies in recombinant human neuroblastoma TRPV1-SHSY5Y cells /." Stockholm : Department of Neurochemistry, Stockholm University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-30182.
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Diss. (sammanfattning) Stockholm : Stockholms universitet, 2009.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: In press. Härtill 4 uppsatser.
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Ibarra, Yessenia Michelle. "Characterization of human TRPA1 and TRPV1 channels in response to naturally occurring defensive compounds." Thesis, Harvard University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3566933.
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The transient receptor potential channels, ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1), are non-selective cation-permeable channels that have retained their function as chemical sensors since their first appearance in metazoan species several hundred million years ago. In vertebrates, TRP channels have evolved multiple functions which make it difficult to understand exactly how they transmit signals to the brain that are interpreted very differently. For example, TRPA1 and TRPV1 are sensitive to various chemicals and activation of these channels produce sensations with opposing effects. Pain is felt when TRPV1 is activated by spider toxins, but activation by plant cannabidiol results in a pain-relieving sensation. Similarly, TRPA1 activation by delta-tetrahydrocannabinol is reported to relieve symptoms of pain, but TRPA1 activation by the active ingredient in wasabi results in a repulsive or noxious sensation. Much of what we know about TRPA1 and TRPV1 comes from the use of plant products or exposure to substances that cause or alleviate pain and inflammation. In this study, whole-cell voltage clamp recordings of heterologously expressed human TRPA1 and human TRPV1 were tested for sensitivity to a hallucinogenic plant compound, salvinorin A and an arthropod-defensive compound, para-benzoquinone. Neither compound has yet been reported to activate TRP channels but both are known to be involved in pain and inflammation signaling in humans. I show that the arthropod compound, para-benzoquinone, activates and desensitizes TRPA1 in a cysteine-dependent manner, but activation of TRPV1 is not dependent on cysteine reactivity. Although salvinorin A is known to be a potent agonist of the kappa-opioid and cannabinoid receptors, here I show that it also acts as a highly potent agonist of both TRPA1 and TRPV1. Its interaction with TRP channels may contribute to its antinociceptive effects in behavioral studies with animals that are reported to be independent of opioid signaling.
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DEMARTINI, CHIARA. "The role of TRPA1 and TRPV1 channels in trigeminal pain: data from animal models." Doctoral thesis, Università degli studi di Pavia, 2018. http://hdl.handle.net/11571/1214824.
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Experimental and clinical observations pointed out a critical involvement of transient receptor potential (TRP) channels, particularly TRPA1 and TRPV1, in trigeminal pain and associated symptoms, including hyperalgesia and allodynia. In this study the role of TRP channels was investigate in two animal models of diseases related to the trigeminal system: migraine and trigeminal neuropathic pain (TNP).
TRPA1 and TRPV1 antagonists (ADM_12 and AMG9810 respectively) were used in the nitroglycerin (NTG)-induced hyperalgesia at the trigeminal level induced by means of the orofacial formalin test, a well validated animal model of migraine. The behavioral effects of AMG9810 gave inconclusive results, probably because its effect was confounded by the vehicle used. Nonetheless, it appears that TRPV1 channels are somehow involved in NTG-induced trigeminal hyperalgesia, since the TRPV1 mRNA levels were found to be strongly increased after NTG injection in medulla, cervical spinal cord and trigeminal ganglia (TG). NTG also up-regulated the mRNA levels of TRPA1, c-fos, calcitonin gene-related peptide (CGRP) and Substance P (SP) in the same areas. Those transcripts, but TRPV1, were reduced after ADM_12 treatment, which abolished the NTG-induced trigeminal hyperalgesia. The increased availability of nitric oxide after NTG promotes the formation of pro-inflammatory agents which can activate and/or sensitize nociceptors by means of TRPA1 and TRPV1 channels, causing the release of CGRP and SP. Although no differences in CGRP and SP protein expression were found at nucleus trigeminalis caudalis (NTC) level, the increased transcripts may reflect compensatory mechanisms aimed at reintegrating CGRP and SP stores depleted after NTG administration. It is possible that ADM_12 caused a reduction of Ca2+ influx through TRPA1 channels, which in turn interfered with the cascade of second-messenger molecules and with the Ca2+-interacting proteins, ultimately preventing NTG-induced inflammatory pathways.
For TNP, the role of TRPA1 channels (by means of ADM_12) was investigated by evaluating mechanical allodynia in a model of chronic constriction injury of the infraorbital nerve (IoN-CCI). The IoN-CCI rats showed a hyperresponsiveness (4 weeks after surgery) at the ipsilateral side that reflects a condition of mechanical allodynia, and a significant increase in TRPA1, TRPV1, CGRP and SP mRNA expression levels. Although a tendency towards a decrease was seen in the ipsilateral compared to the contralateral side in the IoN-CCI rats, no significant differences in CGRP and SP protein expression at the NTC level were seen. However, their transcripts were highly increased in the central areas containing the NTC, as well as the TG ipsilateral to the IoN ligation. Both the allodynic response and the increased mRNA levels of operated rats were abolished after ADM_12 treatment. Probably, the blockade of TRPA1 channels located on the trigeminal afferents prevented neuropeptides release thus resulting in a reduced neurogenic inflammation and the nociceptors sensitization. Contrary to the migraine model, ADM_12 reduced transcript levels of both TRPs in IoN-CCI rats. Thus, ADM_12 appears to be a specific antagonist for TRPA1 in migraine pain, but in TNP it seems to act also on TRPV1. Probably, the damage induced by the nerve injury lead to a re-organization in expression and nature of the channels that made ADM_12 able to block TRPV1 channels. Since TRPA1 and TRPV1 are functionally linked, ADM_12 could have a direct effect on TRPA1 and an indirect effect on TRPV1 channels.
In conclusion, TRPA1 blockade might be useful in the treatment of these trigeminal pain disorders. Moreover, our data suggest an important role also for TRPV1 channels, which could be differently involved depending on the type of pain. Further exploration on the mechanisms underlying the antinociceptive effects of these TRPs should improve our understanding of trigeminal pain processing.Experimental and clinical observations pointed out a critical involvement of transient receptor potential (TRP) channels, particularly TRPA1 and TRPV1, in trigeminal pain and associated symptoms, including hyperalgesia and allodynia. In this study the role of TRP channels was investigate in two animal models of diseases related to the trigeminal system: migraine and trigeminal neuropathic pain (TNP). TRPA1 and TRPV1 antagonists (ADM_12 and AMG9810 respectively) were used in the nitroglycerin (NTG)-induced hyperalgesia at the trigeminal level induced by means of the orofacial formalin test, a well validated animal model of migraine. The behavioral effects of AMG9810 gave inconclusive results, probably because its effect was confounded by the vehicle used. Nonetheless, it appears that TRPV1 channels are somehow involved in NTG-induced trigeminal hyperalgesia, since the TRPV1 mRNA levels were found to be strongly increased after NTG injection in medulla, cervical spinal cord and trigeminal ganglia (TG). NTG also up-regulated the mRNA levels of TRPA1, c-fos, calcitonin gene-related peptide (CGRP) and Substance P (SP) in the same areas. Those transcripts, but TRPV1, were reduced after ADM_12 treatment, which abolished the NTG-induced trigeminal hyperalgesia. The increased availability of nitric oxide after NTG promotes the formation of pro-inflammatory agents which can activate and/or sensitize nociceptors by means of TRPA1 and TRPV1 channels, causing the release of CGRP and SP. Although no differences in CGRP and SP protein expression were found at nucleus trigeminalis caudalis (NTC) level, the increased transcripts may reflect compensatory mechanisms aimed at reintegrating CGRP and SP stores depleted after NTG administration. It is possible that ADM_12 caused a reduction of Ca2+ influx through TRPA1 channels, which in turn interfered with the cascade of second-messenger molecules and with the Ca2+-interacting proteins, ultimately preventing NTG-induced inflammatory pathways. For TNP, the role of TRPA1 channels (by means of ADM_12) was investigated by evaluating mechanical allodynia in a model of chronic constriction injury of the infraorbital nerve (IoN-CCI). The IoN-CCI rats showed a hyperresponsiveness (4 weeks after surgery) at the ipsilateral side that reflects a condition of mechanical allodynia, and a significant increase in TRPA1, TRPV1, CGRP and SP mRNA expression levels. Although a tendency towards a decrease was seen in the ipsilateral compared to the contralateral side in the IoN-CCI rats, no significant differences in CGRP and SP protein expression at the NTC level were seen. However, their transcripts were highly increased in the central areas containing the NTC, as well as the TG ipsilateral to the IoN ligation. Both the allodynic response and the increased mRNA levels of operated rats were abolished after ADM_12 treatment. Probably, the blockade of TRPA1 channels located on the trigeminal afferents prevented neuropeptides release thus resulting in a reduced neurogenic inflammation and the nociceptors sensitization. Contrary to the migraine model, ADM_12 reduced transcript levels of both TRPs in IoN-CCI rats. Thus, ADM_12 appears to be a specific antagonist for TRPA1 in migraine pain, but in TNP it seems to act also on TRPV1. Probably, the damage induced by the nerve injury lead to a re-organization in expression and nature of the channels that made ADM_12 able to block TRPV1 channels. Since TRPA1 and TRPV1 are functionally linked, ADM_12 could have a direct effect on TRPA1 and an indirect effect on TRPV1 channels. In conclusion, TRPA1 blockade might be useful in the treatment of these trigeminal pain disorders. Moreover, our data suggest an important role also for TRPV1 channels, which could be differently involved depending on the type of pain. Further exploration on the mechanisms underlying the antinociceptive effects of these TRPs should improve our understanding of trigeminal pain processing.
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Cao, Deshou. "Role of Transient Receptor Potential (TRP) Channels in Nociception." OpenSIUC, 2009. https://opensiuc.lib.siu.edu/dissertations/71.
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Transient receptor potential (TRP) channels play an important role in sensory and nonsensory functions. TRPVanilloid 1 and TRPVanilloid 4 are proposed to be involved in inflammation-induced pain. TRPV1 is extensively studied and it is specifically involved in inflammatory thermal hypersensitivity. Mechanical hypersensitivity is one of the significant components of nociception. Several receptors have been proposed to underlie mechanosensation. The molecular entities responsible for mechanosensation are not fully understood. In this study, I have characterized the properties of TRPV4, a putative mechanosensitive ion channel expressed in dorsal root ganglion (DRG) neurons and nonsensory tissues. First, I have investigated the expression and function of TRPV4 and TRPV1 in the DRG neuronal cell bodies as well as their central terminals and determined the modulation by protein kinase C (PKC). Both TRPV4 and TRPV1 are expressed in DRG and laminae I and II of the spinal dorsal horn (DH). Ca2+ fluorescence imaging and whole-cell patch-clamp experiments showed that both capsaicin-induced TRPV1 response and 4alpha-phorbol 12, 13-didecanoate (4alpha-PDD)-induced TRPV4 response were observed in a proportion of the same DRG neurons, suggesting their co-expression. Incubation of DRG neurons with phorbol 12, 13-dibutyrate (PDBu), a PKC activator, resulted in a significantly greater potentiation of TRPV4 currents than TRPV1 currents. In HEK cells heterologously expressing TRPV4, PDBu potentiated TRPV4-mediated single-channel current activity. In patch-clamped DH neurons, the application of 4alpha-PDD at the first sensory synapse increased the frequency but not the amplitude of the miniature excitatory postsynaptic currents (mEPSCs), suggesting a presynaptic locus of action. 4alpha-PDD-induced increase in the frequency of mEPSC was further facilitated by PDBu. These results suggest that TRPV4 in the central terminals modulates synaptic transmission and is regulated by PKC. Second, I have studied the mechanosensitivity of TRPV4 in cell-attached patches by applying direct mechanical force via the patch pipette. In TRPV4 expressing HEK cells, the application of negative pressure evoked single-channel current activity in a reversible manner and the channel activity was enhanced after incubation with PDBu. TRPV4 has been shown to be activated by hypotonicity. Here I show that negative pressure exaggerated hypotonicity-induced single-channel current activity. However, in similar experimental conditions, cells expressing TRPV1 did not respond to mechanical force. TRP channels are also expressed in non-sensory regions and the role of these channels is not fully understood. Both TRPV4 and TRPV1 are expressed in the hippocampus. Using whole-cell patch-clamp techniques, I have found that 4alpha-PDD increased the frequency, but not the amplitude of mEPSCs in cultured hippocampal neurons, suggesting a presynaptic site of action. Interestingly, the application of capsaicin had no effect on synaptic transmission in hippocampal neuronal cultures. Finally, I have investigated the expression and function of TRP channels in diabetes because TRP channels have been shown to be involved in peripheral neuropathy as well as vascular complications in diabetes. ROS production plays a critical role in the progress of diabetes. I propose that lower levels of ROS up-regulate the expression TRP channels in the early stages of diabetes, leading to hyperalgesia, and higher levels of ROS or chronic exposure to ROS down-regulate TRP channels in the late stages of diabetes, resulting in hypoalgesia. I have found that the expression of TRPV1 and phospho p38 (p-p38) MAPK was increased in DRG of streptozotocin (STZ)-injected diabetic and non-diabetic hyperalgesic mice. An increase in TRPV1 and p-p38 MAPK levels was induced by STZ or H2O2 treatment in stably TRPV1 expressing HEK cells, suggesting the involvement of STZ-ROS-p38MAPK pathway. TRPV4 has been reported to be involved in vasodilatation by shear stress in blood vessels. Here, I have demonstrated that TRPV4 is expressed in lymphatic endothelial cells (LECs). Treatment with low concentration of H2O2 enhanced the expression of TRPV4 at mRNA and protein levels in LECs, suggesting that mild levels of ROS up-regulate TRPV4 expression. In diabetes, beta cell dysfunction is responsible for decreased insulin release. TRPV4 is expressed in RINm5F (beta cell line), islets and pancreas. It has been shown that hypotonicity induced insulin release in beta cell lines, which was mediated by activation of stretch-activated channels, raising the possibility of the involvement of TRPV4, a mechanosensitive channel. Therefore, I have studied the functional role of TRPV4 in beta cells. Incubation with 4alpha-PDD enhanced insulin release in RINm5F cells, suggesting TRPV4 regulates insulin secretion from pancreatic beta cells. Since TRPV4 expression levels are decreased in diabetes, insulin secretion from beta cells may be impaired. In summary, TRPV1, a thermosensitive channel, and TRPV4, a mechanosensitive channel, contribute to thermal and mechanical hyperalgesia, respectively in the early stage of DPN through their up-regulation by ROS-p38 MAPK and insulin/IGF-1 pathways. Due to the mechanical sensitivity of TRPV4 channel, the up-regulation in the early stage and down-regulation in the late stage may be involved in the development of vascular complications and regulation of insulin release in diabetes.
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Leonelli, Mauro. "Receptores vanilóides TRPV1 na retina." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42137/tde-22072011-131242/.
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A expressão do receptor de potencial receptor transiente, vanilóide 1 (TRPV1) começa desde estágios pré-sinaptogênicos da retina. O bloqueio farmacológico desse receptor nesse período diminui a apoptose fisiológica, havendo possível envolvimento da sinalização de MAP quinases. Na retina do animal adulto, observamos que a expressão de TRPV1 é amplamente difundida, albergando neurônios, células endoteliais e células da microglia. A ativação dos receptores TRPV1 é potencialmente citotóxica, e os mecanismos que podem estar envolvidos incluem a liberação de glutamato, a excitotoxicidade e o estresse nitrosativo. Evidenciamos que a lesão prévia de células ganglionares sensibiliza o tecido retiniano à citotoxicidade mediada pela estimulação de TRPV1. Porém, o bloqueio de TRPV1, tanto in vivo quanto in vitro, não inibiu a morte de células ganglionares axotomizadas. Esses dados sugerem que o receptor TRPV1 participa da modulação de diversos processos fisiopatológicos na retina.TRPV1 expression in the developing retina begins before retinal sinaptogenesis. TRPV1 blockade reduced the normal apoptosis in this period, and MAPK signaling seems to be involved in this process. In the adult retina, TRPV1 are expressed in neuronal, endothelial and microglial cells. The activation of those receptors is potentially cytotoxic, and glutamate release and further excitotoxicity and nitrosative stress might be also involved. Axotomized retinal ganglion cells were sensitized to TRPV1 citotoxicity, but TRPV1 antagonism, both in vitro and in vivo, did not reduce the loss of ganglion cell after axotomy. Our results suggest that TRPV1 receptors are involved in synaptic function and homeostatic control in the retina. Moreover, TRPV1 seems to be indirectly involved in cellular degeneration that follows the section of retinal ganglion cell axons.
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Goswami, Chandan. "Identification of tubulin as a TRPV1-interacting protein and functional characterization of TRPV1-cytoskeleton regulation." [S.l.] : [s.n.], 2006. http://www.diss.fu-berlin.de/2006/315/index.html.
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Rosano, Giulio. "Structure-function studies of TRPV1 alcohol modulation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19298/.
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The TRPV1 channel is a member of the Transient Receptor Potential (TRP) family of cation channels and is responsible for the perception of different noxious stimuli. It is mainly found in the peripheral terminals of primary sensory neurons where pain is produced and in various brain regions such as hypothalamus, cerebellum and cerebralcortex.
It can be activated by a large number of physical and chemical stimuli and themost known ones include capsaicin (the active component of hot chili peppers), noxiousheat (greater than 42◦C), voltage and acidity. There is now evidence of how ethanol can potentiate TRPV1 activity when activatedby low pH (inflammation) and capsaicin, and how it can lower the temperature thresholdactivation when activated by heat. It is also known that different alcohol moleculescan affect many biophysical processes, including the kinetics of ion channels acting aspositive allosteric modulators, therefore, it is important to determine how the proprietiesof such receptors change when alcohol molecules interact with the system. Following this path, the aim of this project is to optimize a protocol which can later be used for a simpler TRPV1 expression on Xenopus laevis oocytes in order to perform experiments of electrophysiology (TEVC). Once this is achieved, using the TEVC method, it will bepossible to determine how alcohol modulates TRPV1 by figuring out the alcohol cut-off size (the maximum size alcohol that can bind and modulate to the channel) that couldindicate a direct alcohol binding site on the channel. Through this step and others that will follow in this direction, a new way of understanding pain can be accomplished by formulating more pain-inhibiting drugs that can act on additional specific sites.
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Schwarz, Holger Jens [Verfasser], and Bela [Akademischer Betreuer] Szabo. "Die Rolle des TRPV1-Rezeptors im Cerebellumcortex." Freiburg : Universität, 2016. http://d-nb.info/1119806062/34.
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Pritchard, Sara. "Modulation of TRPV1 function in sensory neuropathy." Thesis, University of Hertfordshire, 2015. http://hdl.handle.net/2299/15360.
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This thesis examined how and why TRPV1 function is being modulated in sensory neuropathy and explored the potential of its rescue in the urinary bladder of STZ-‐induced diabetic rats. Diabetes induced a rapid decline in TRPV1 function and changes in neurogenically mediated electrically-‐evoked responses together with a gradual decline in muscarinic function. Diabetic bladder was also deficient in muscarinic and TRPV1 organ bath temperature-‐induced changes but not in those affecting spontaneous contractile activity. Exposure to a potential neuropathy causative agent, methylglyoxal was studied and its mechanism of action explored through the use of TRPA1 ligands. Methylglyoxal exposure mimicked some of the effects of diabetes on TRPV1, neurogenic electrically evoked responses and muscarinic function. Methylglyoxal effects were seen to be partly through TRPA1 receptor activation but other as yet undefined pathways were also involved. Use of TRPA1 ligands revealed an unexpected complexity of the interaction of the TRPA1 receptor with TRPV1. Finally the potential of reversing the diminished TRPV1 response was examined through the use of three known sensitising agents, bradykinin, NGF and insulin. Bradykinin was the only agent seen to reverse the TRPV1 diminished response back up to to control equivalent levels and through the use of bradykinin selective ligands, it was seen that the dual activation of BK-‐1 and BK-‐2 receptor was necessary to rescue the TRPV1 response. The likely mechanism of action of bradykinin was through prostaglandin production as indomethacin blocked TRPV1 rescue. In the acute stage of diabetes, TRPV1 function is downregulated and may be caused by exposure to a neuropathy-‐causing metabolite such as methylglyoxal. The TRPV1 function still retains plasticity at this acute stage because function could be enhanced back to control levels by bradykinin receptor activation : a potential for early therapeutic intervention.
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Saffran, Alexander. "Activation of TRPV1 by Capsaicin Regulates ENaC." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5544.
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ENaC is a constitutively open heterotrimeric channel which regulates Na+ transport in tight epithelia of the kidney, lungs, colon and anterior tongue containing fungiform taste buds. The amiloride-sensitive ENaC is comprised of aβg subunits. Humans express an additional subunit, the d subunit. Therefore, humans contain both aβg-ENaC and dβg-ENaC functional channels. Relative to aβg-ENaC, the dβg-ENaC is 10-fold less sensitive to amiloride. In the mammalian anterior tongue, ENaC is expressed in fungiform salt sensing taste receptor cells and is the Na+-specific salt taste receptor. In mammals, salt elicits an inverted U shaped behavioral response. Lower concentrations of salt are appetitive while high salt concentrations are aversive. The appetitive salt concentrations are sensed via ENaC. Thus, modulating ENaC activity in fungiform taste receptor cells will, in turn, regulate salt intake. The aim of this project is to investigate the effect of a common food ingredient, capsaicin, on ENaC expression and function in two cell lines, HEK293 cells and cultured adult human fungiform taste bud cells (HBO cells). Capsaicin, a TRPV1 agonist was chosen because in previous studies, it modulated chorda tympani taste nerve responses to NaCl in a dose-dependent manner. Most importantly, capsaicin and other agonists of TRPV1 were effective in modulating human salt taste perception. It is likely that the effect of capsaicin is due to its interactions with TRPV1, because TRPV1 and ENaC subunits are co-expressed in cortical collecting duct cells (CCD) and in a subset of human taste bud cells. In support of this hypothesis, TRPV1 has been shown to regulate ENaC expression and function in CCD cells of rats and mice. Using immunohistochemical techniques, our results demonstrate that TRPV1 is co-localized with the d-ENaC subunit in HBO cells. Additionally, the results in HEK-293 cells suggest that the activation of TRPV1 via capsaicin has a modulatory effect on d-ENaC mRNA and protein expression as well ENaC channel function measured as Na+ flux.
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Hadrovic, Banina. "A study of TRPV1 and TRPV4 ion channels in the beta cells by using fura-2 based microfluorometry." Thesis, Mälardalen University, School of Sustainable Development of Society and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-7350.
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The calcium ion (Ca2+) is an important ion that regulates many cellular functions including exocytosis, contraction of muscles, neural functions, fertilization and cell division. In the plasma membrane of cells there are different Ca2+ channels, including the transient receptor potential (TRP) family of cation channels. The TRP channels are activated by physical stimuli like temperature, stretch, osmolality, and also various ligands. These channels are divided into seven subfamilies, namely TRPC, TRPV, TRPM, TRPML, TRPA, TRPP, and TRPN.
TRP channels can regulate the cytoplasmic free Ca2+ concentration ([Ca2+]i) and are therefore important for research of insulin secretion from beta (β) cells. With TRP research new and more effective treatment methods for people with diabetes can be developed. People with type 2 diabetes have a decreased insulin secretion from beta (β) cells, in response to glucose. Cytoplasmic free Ca2+ concentration ([Ca2+]i) is important for insulin secretion. It is therefore desirable to find compounds that can increase [Ca2+]i in pancreatic β cells and thereby increase insulin secretion.
The aim of this project was to investigate whether pancreatic β cells express TRPV1 and TRPV4 ion channels. If the channels are expressed in β cells the [Ca2+]i can be increased by identifying substances that stimulate TRPV1 and TRPV4 channels. The results can then be used for providing better treatment for patients with diabetes type 2. Insulinoma cells from rat (S5 cells) were used as a model for β cells. [Ca2+]i was measured from single fura-2 loaded S5 cells by ratiometric microfluorometry. To test whether TRPV1 is expressed,
N-(4-hydroxyphenyl)-Arachidonoylamide (AM404) and [5-hydroxyl-1-(4-hydroxy-3-methoxyphenyl)decan-3-one] ([6]-gingerol) were used. To test whether TRPV4 was expressed, a TRPV4-selective agonist 4alpha-Phorbol 12,13-Didecanoate namely 4α–PDD was used.
The two agonist of TRPV1, AM404 and [6]-gingerol increased [Ca2+]i . Capsaicin a classical activator of TRPV1 used as a control also increased [Ca2+]i . These increases were inhibited by capsazepine, a specific blocker of TRPV1. 4α–PDD, a specific agonist of TRPV4 also increased [Ca2+]i. These results suggest that S5 cells express both TRPV1 and TRPV4 channels and that AM404, [6]-gingerol and 4α–PDD are potential substances for increasing the insulin secretion from β cells.
Kalciumjonen (Ca2+) är en viktig jon och förmedlar signaler i processer som cellutsöndring, muskelkontraktion, nervfunktion, fertilisering och celldelning. I cellers plasmamembran finns det olika sorters Ca2+ -kanaler, inklusive transient receptor potential (TRP) jonkanalerna. TRP kanalerna aktiveras av fysisk stimulans, så som temperatur, utsträckning, osmolalitet men också av olika ligander. TRP kanalerna är indelade i sju underfamiljer, TRPC, TRPV, TRPM, TRPML, TRPA, TRPP,och TRPN.
TRP kanalerna reglerar den fria Ca2+ koncentrationen ([Ca2+]i) i cytoplasman och är därmed viktiga för forskning inom insulinutsöndringen från beta (β) celler. Med denna forskning kan nya och effektivare behandlingsmetoder för personer med diabetes utvecklas. Personer med typ 2 diabetes har bl.a. en minskad insulinfrisättning i beta (β) celler som orsakar en glukosökning i blodet. Den fria Ca2+ -koncentrationen ([Ca2+]i) i cytoplasman är viktig för insulinfrisättningen. Det är därför önskvärt att hitta kemiska föreningar som kan bidra till en ökning av [Ca2+]i i bukspottkörtelns β celler och därmed också ge en ökad insulinfrisättning.
Målet med detta projekt har varit att undersöka om β celler från bukspottkörtel uttrycker jonkanalerna TRPV1 och TRPV4. Om β celler uttrycker dessa kanaler kan [Ca2+]i i cytoplasman ökas genom att identifiera substanser som stimulerar just TRPV1 och TRPV4 kanaler. Resultaten kan användas för att bidra med bättre behandling till diabetespatienter med typ 2 diabetes. Tumoriserade celler från råtta (S5) användes som modell för β celler. [Ca2+]i mättes från enskilda fura-2 laddade S5 celler med hjälp av ett ratiometriskt mikrofluorometriskt system. För att undersöka om TRPV1 finns testades ämnena N-(4-hydroxyphenyl)-Arachidonoylamide (AM404) och [5-hydroxyl-1-(4-hydroxy-3-methoxyphenyl)decan-3-one] ([6]-gingerol). För att undersöka om TRPV4 finns användes det TRPV4-specifika ämnet (4alpha-Phorbol 12,13-Didecanoate)
4α–PDD.
De båda TRPV1 agonisterna AM404 och [6]-gingerol inducerade en ökning i [Ca2+]i. Capsaicin som är en klassisk TRPV1 agonist ökade också [Ca2+]i och användes som kontroll. Alla dessa koncentrationsökningar inhiberades av capsazepine, som är en TRPV1- antagonist. 4α–PDD som är en specifik TRPV4 agonist ökade också [Ca2+]i.
Resultaten tyder på att S5 cellerna uttrycker både TRPV1 och TRPV4 kanaler samt att AM404, [6]-gingerol och 4α–PDD är alla substanser med potential att öka insulinfrisättningen från bukspottkörtelns β celler.
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Niedermirtl, Florian [Verfasser], and Carla [Akademischer Betreuer] Nau. "Das intravenöse Anästhetikum Propofol aktiviert nozizeptive Neurone über TRPA1-, TRPV1- und GABAA-Rezeptoren / Florian Niedermirtl. Betreuer: Carla Nau." Erlangen : Universitätsbibliothek der Universität Erlangen-Nürnberg, 2011. http://d-nb.info/1018309101/34.
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Wong, Benjamin. "Functional roles of different TRPV1 populations in calcium signalling of rat sensory neurons and HEK 293 cells expressing rat TRPV1." Thesis, University of Hertfordshire, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632998.
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The TRPV1 vanilloid receptor is thought to be expressed on both plasmalemmal (TRPV1PM) and intracellular (TRPV1ER) membranes. Membrane-impermeable TRPV1PM restricted antagonists (SB-497794-D and ruthenium red) were used to investigate the functional roles of TRPV1PM and TRPV1ER in capsaicin-activated calcium signalling of TRPV1-expressing cells (rat DRG neurons and rat TRPV1-expressing HEK 293 cells). The ability of TRPV1PM restricted antagonists to completely block capsaicin activation of TRPV1PM when TRPV1-expressing cells were challenged with capsaicin enabled the remaining capsaicin-activated TRPV1ER response to be assessed. The intracellular calcium imaging study that investigated the effect of 10 μM SB-497794-D against 1 μM capsaicin on rat TRPV1-expressing HEK 293 cells, in the presence of extracellular calcium, showed no contribution from TRPV1ER. In contrast, SB-497794-D (10 and 50 μM) and ruthenium red (10 and 100 μM) produced similar effects against 1 μM capsaicin on rat DRG neurons; these intracellular calcium imaging studies revealed that in the presence of extracellular calcium, the 1 μM capsaicin-induced intracellular calcium rise of rat DRG neurons was 70 % attributable to TRPV1PM, whereas the remaining 30 % calcium response was not blocked and hence mediated by TRPV1ER. However, in the absence of extracellular calcium, capsaicin (1 and 20 μM) failed to induce a TRPV1ER-mediated intracellular calcium response in the rat DRG neurons, suggesting that the TRPV1ER response is regulated by extracellular calcium. Intriguingly, the organ bath study that investigated the effect of 50 μM SB-497794-D against capsaicin-induced contraction of rat bladder strips demonstrated the ability of SB-497794-D to completely inhibit capsaicin-induced contraction of rat bladder strips. This suggests that TRPV1ER has no contribution to the capsaicin responses in this intact sensory nerve preparation. The clinical demonstration of azelastine to inhibit capsaicin-induced cough in cough patients suggests that this histamine-1 (H1) receptor antagonist has off-target antagonist effects at the putative TRPV1 cough receptor. Interestingly, two other H1 receptor antagonists (dexbrompheniramine maleate and chlorpheniramine) have recently been reported to have TRPV1 antagonist effects. FLIPR (Fluorescence Imaging Plate Reader) studies investigating the effect of azelastine against capsaicin on human and rat TRPV1, each expressed separately in HEK 293 cells, were conducted to address whether azelastine exerts off-target TRPV1 antagonism. Furthermore, the individual effects of other H1 receptor antagonists (dexbrompheniramine maleate, chlorpheniramine, mepyramine and olopatadine) against capsaicin on human and rat TRPV1 were investigated with the FLIPR assay to determine whether these H1 receptor antagonists have off-target TRPV1 antagonist effects. The FLIPR assay demonstrated the off-target TRPV1 antagonism of four H1 receptor antagonists (azelastine, dexbrompheniramine maleate, chlorpheniramine and mepyramine, but not olopatadine) against capsaicin activation of human and rat TRPV1. The off-target TRPV1 antagonism of dexbrompheniramine maleate was further demonstrated by the ability of dexbrompheniramine maleate (at 100 μM) to completely block the full capsaicin concentration-response curve for capsaicin-induced TRPV1-mediated contraction of rat bladder strips. Thus, it is likely that dexbrompheniramine maleate inhibited capsaicin activation of TRPV1PM in the bladder innervating primary sensory neurons to block the capsaicin-induced contraction of rat bladder strips.
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Leffler, Andreas. "TRPV1 ist ein polymodaler Rezeptor von nozizeptiven Spinalganglienzellen." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972880216.
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Hanack, Christina [Verfasser]. "Proteomics reveal insights into TRPV1 function / Christina Hanack." Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1050978390/34.
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Païta, Lucille. "Caractérisation du canal cationique TRPV1 dans les cardiomyocytes." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1329/document.
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L'infarctus du myocarde, une des causes majeures de mortalité à travers le monde, engendre une mort irréversible du muscle cardiaque suite à une ischémie. Cette ischémie, c'est-à-dire une privation de dioxygène et de nutriments, déclencher un stress réticulaire qui perturbe l'équilibre calcique de la cellule cardiaque. Plusieurs pompes et canaux calciques situés à la membrane plasmique ou réticulaire sont des intervenants clés dans le maintien de l'homéostasie calcique. Parmi eux, il existe des canaux de fuites calciques passives, comme les TRPs, et peu d'informations sont actuellement connus à propos de leur rôle précis au cours de l'infarctus du myocarde.TRPV1 est un canal cationique non sélectif qui est activé par la capsaïcine, le pH et la chaleur nocive (>42°C). Dans le muscle squelettique, nous avions démontré que TRPV1 est situé dans la partie longitudinale du réticulum sarcoplasmique et qu'il répond à différentes stimulations physiologiques et pharmacologiques (Lotteau et al., 2013). Ici, nous nous interrogeons sur un éventuel rôle similaire de TRPV1 dans la physiologie cardiaque. Des analyses biochimiques et des mesures de calcium intracellulaire furent réalisées sur des cardiomyocytes issus de souris WT et KO TRPV1. Nos résultats in vitro montrent que: (a) TRPV1 est exprimé dans les cellules cardiaques; (b) une activation de TRPV1 engendre une réduction de la concentration calcique réticulaire et que (c) TRPV1 pourrait être une cible directe de l'isoflurane.Dans la mesure où TRPV1 peut être modulé par de nombreuses molécules pharmacologiques, il pourrait constituer une cible thérapeutique pour réduire la taille d'infarctus. De nombreuses études antérieures ont déjà mis en évidence un rôle cardioprotecteur de TRPV1 dans le système nerveux entourant le cœur. Le but de cette étude est de décrire le fonctionnement des canaux TRPV1 dans des cardiomyocytes adultesAcute myocardial infarction (MI), a leading cause of morbidity and mortality worldwide, is the irreversible death of heart muscle secondary to ischemia. This ischemia, i.e. oxygen and nutrients deprivation, triggers a reticular stress disrupting the Ca2+ balance of the cardiac cell. Several Ca2+ pumps and channels located at the sarcolemma or at the reticulum membrane are key players in this maintenance of Ca2+ homeostasis. Among them, we find passive leak channels, such as TRPs and little is known about their precise role in MI.TRPV1 represents a non-selective cation channel that is activated by capsaicin, pH and noxious heat. In skeletal muscle, we previously demonstrated that TRPV1 is located in the longitudinal part of the SR and respond to pharmacological and physiological activations (Lotteau et al., 2013). We questioned here whether TRPV1 might have a similar role in heart physiology. Biochemical analysis and intracellular Ca2+ measurements were performed on cardiomyocytes from wild-type and TRPV1-KO mice. Our in vitro results show that: (i) TRPV1 is expressed in cardiac cells; (ii) an increase in intracellular calcium concentration ([Ca2+]i) is elicited under TRPV1 activation; (iii) TRPV1 could be a direct target of isoflurane. In parallel, our in vivo results indicate that a pharmacological preconditioning by isoflurane decrease the infarct size, probably though activation of TRPV1. According to the fact that TRPV1 activity can be modulated by a lot of pharmacological molecules, TRPV1 may serve as therapeutic target to reduce the infarct size. Most of published data have already evidenced this TRPV1 cardioprotective role in the peripheral heart system. The aim of the present work is to describe how TRPV1 channels behave in adult cardiomyocytes
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Jorge, Carolina Ocanha 1990. "Envolvimento dos receptores TRPV1 e TRPA1 na hiperalgesia muscular induzida pela contração isométrica sustentada no músculo gastrocnêmio de ratos." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/244490.
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Orientadores: Maria Cláudia Gonçalves de Oliveira Fusaro, Andrea Maculano EstevesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas
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Resumo: A dor musculoesquelética é um importante problema de saúde mundial. Dentre todos os tipos de dor, àquela induzida pela contração isométrica sustentada está relacionada com os movimentos corporais nas atividades da vida diárias e apresenta um alto impacto socioeconômico. Apesar da sua relevância clínica, os mecanismos moleculares envolvidos no desenvolvimento da dor muscular induzida pela contração isométrica sustentada são pouco conhecidos. Portanto, o objetivo deste estudo foi avaliar o envolvimento dos receptores TRPV1 e TRPA1 na hiperalgesia muscular mecânica induzida pela contração isométrica sustentada no músculo gastrocnêmio de ratos machos, da linhagem wistar. O antagonista seletivo do receptor TRPV1, AMG9810, reduziu significativamente a hiperalgesia muscular mecânica induzida pela contração isométrica sustentada quando administrado no músculo gastrocnêmio ipsilateral, mas não no contralateral. A administração intratecal de AMG9810 apresentou a mesma resposta. Similar ao TRPV1, a administração intramuscular e intratecal do antagonista seletivo do receptor TRPA1, HC030031, reduziu significativamente a hiperalgesia muscular induzida pela contração isométrica sustentada. No entanto, não foi observado modificação da expressão proteica dos receptores TRPV1 e TRPA1 no tecido muscular após a contração isométrica sustentada. Os dados sugerem que os receptores TRPV1 e TRPA1 expressos no músculo gastrocnêmio e corno dorsal da medula espinhal estão envolvidos na hiperalgesia muscular mecânica induzida pela contração isométrica sustentada em ratos. Sugerimos, portanto, que os receptores TRPV1 e TRPA1 co-expressos nas fibras aferentes primárias trabalhem juntos para ativar os nociceptores das fibras aferentes durante a contração isométrica sustentada. Além disso, nós sugerimos que os receptores TRPV1 e TRPA1 sejam potenciais alvos para o controle da dor muscular inflamatória
Abstract: Musculoskeletal pain is an important health issue in the world. Among the kinds of muscle pain, the one induced by sustained isometric contraction is associated with body movements of the daily life and has a high socio-economic impact. Despite its clinical relevance, the molecular mechanisms involved in the development of muscle pain induced by sustained isometric contraction are poorly understood. Therefore, the aim of this study was to evaluate the involvement of TRPV1 and TRPA1 receptors in the mechanical muscle hyperalgesia induced by sustained isometric contraction of the gastrocnemius muscle of rats. The selective TRPV1 receptor antagonist AMG 9810 reduced the mechanical muscle hyperalgesia induced by sustained isometric contraction when administered in the ipsilateral but not in the contralateral gastrocnemius muscle. Also, the intratecal administration of AMG9810 reduced the same response. Similar to TRPV1, intramuscular and intrathecal administration of selective TRPA1 receptor antagonist HC030031 reduced the mechanical muscle hyperalgesia induced by sustained isometric contraction. Finally, the sustained isometric contraction did not modify the protein expression of TRPV1 and TRPA1 receptors in muscle tissue. We concluded that TRPV1 and TRPA1 receptors expressed in gastrocnemius muscle and spinal cord dorsal horn are involved with the mechanical muscle hyperalgesia induced by sustained isometric contraction in rats. We suggest that TRPV1 and TRPA1 receptors co-expressed in primary afferent fibers work together to activate nociceptive afferent fibers during sustained isometric contraction. Also, we suggest that TRPV1 and TRPA1 receptors are potential target to control inflammatory muscle pain
Mestrado
Biodinâmica do Movimento Humano e Esporte
Mestra em Ciências da Nutrição e do Esporte e Metabolismo
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Gu, C. "Signalling pathways underlying sensitization of TRPV1 by RET receptors." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599771.
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Here I report that artemin, a member of the glial cell line-derived neurontrophic factor (GDNF) family, can potentiate TRPV1 activity. Analysis of capsaicin-evoked Ca2+ transients in isolated mouse dorsal root ganglion (DRG) neurons and neuro-2a cells revealed a rapid, potent and prolonged sensitization caused by artemin (~60% cells sensitized with ~2-fold increase in peak response to capsaicin). The mechanism of sensitization of TRPV1 by artemin was further investigated by observing the effects of inhibitors of potential members of artemin-activated second messenger signalling pathways. Pharmacological blockade of PKC, PI3K and Src kinase all prevented enhancement of the capsaicin response evoked by artemin, whereas inhibition of PKA, MAPK and Akt had no effect on sensitization. These and other data support the hypothesis that sensitization of TRPV1 by artemin is mediated by two pathways: tyrosine kinase signalling cascades involving PKCδ, PI3K and Src kinase are the major mediators of artemin induced TRPV1 sensitization in sensory neurons, whereas the PLCδ/PKCε signalling pathway has a smaller effect. The cytoskeletal protein β-actin was found to be associated with immunoprecipitated TRPV1 and the interaction between TRPV1 and actin was enhanced after exposure to artemin. The enhancement of membrane expression of TRPV1 can be blocked by the specific actin inhibitor, Latrunculin B (1 μM), both in a biotinylation assay and in calcium imaging, which suggests that β-actin may be involved in artemin-induced TRPV1 translocation. These findings give us a further insight into ongoing molecular events during thermal hyperalgesia and inflammatory pain and may provide a molecular basis for the development of effective drugs in treating such pain.
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CABRAL, Layla Dutra Marinho. "Influência do receptor vanilóide tipo 1 (TRPV1) na endotoxemia." Universidade Federal de Alfenas, 2016. https://bdtd.unifal-mg.edu.br:8443/handle/tede/997.
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A presença de endotoxina bacteriana na corrente circulatória é associada ao início e
manutenção da sepse, condição complexa e heterogênea que promove a liberação de
mediadores inflamatórios, os quais conduzem a alterações no sistema nervoso central e
subsequente resposta imunológica inflamatória desequilibrada, com desencadeamento da
síndrome da disfunção de múltiplos órgãos (SDMO). Os receptores TRPV1, por sua vez,
participam da modulação de diversos sistemas e podem influenciar processos fisiológicos
comprometidos por inflamação, representando potencial alvo terapêutico. O objetivo do
estudo foi avaliar a participação dos receptores TRPV1 na lesão pulmonar aguda/síndrome do
desconforto respiratório agudo (LPA/SDRA) e no comportamento doentio induzidos por
endotoxina por meio do bloqueio de tais receptores com capsazepina (CPZ) em camundongos.
No tocante à LPA/SDRA, os camundongos tiveram lesão induzida por LPS 5,0mg/kg com
simultânea aplicação de CPZ e foram submetidos à análise após 24 horas. Foi observada a
redução das resistências do sistema e tecidual, além da diminuição do colapso alveolar com o
bloqueio dos receptores TRPV1, evidenciando a modulação da LPA/SDRA por esses
receptores. Em relação ao comportamento doentio, camundongos receberam administração de
CPZ 30 minutos antes da aplicação de LPS 200μg/kg, e após 2 horas foram submetidos aos
testes comportamentais, coleta de sangue e tecidos. Observou-se que a administração do
bloqueador atenuou os efeitos tipo-ansiosos e depressivos, o aumento de temperatura corporal
e a expressão de c-fos em algumas áreas encefálicas induzidos pelo LPS. Entretanto, a CPZ
não promoveu alterações na mobilidade, ingestão alimentar, ganho de peso, níveis
plasmáticos de citocinas e expressão proteica dos receptores no hipocampo e hipotálamo.
Tais resultados sugerem a participação dos receptores TRPV1 na modulação do
comportamento doentio, na regulação da temperatura corporal e na mecânica respiratória após
desafio imunológico.Bacterial endotoxin presence in the bloodstream is associated with the onset and maintenance of sepsis, complex and heterogeneous condition that promotes the release of inflammatory mediators, which lead to changes in the central nervous system and subsequent unbalanced inflammatory immune response, with consequent multiple organ failure. The TRPV1 receptor, in turn, participate in the modulation of different systems and can influence physiological processes impaired by inflammation, and so represent a potential therapeutic target. The aim of the study was to evaluate the involvement of TRPV1 receptors in acute lung injury/ acute respiratory distress syndrome (ALI/ARDS) and in the sickness behavior induced by endotoxin, with the blockade by capsazepine (CPZ) in mice. Regarding the ALI/ARDS, animals had the disease induced by LPS 5.0mg/kg with simultaneous application of CPZ and were analyzed after 24 hours. Reduced resistance of the system and tissue was observed, in addition to decreased alveolar collapse by the blockade of TRPV1 receptors, showing a modulation by these receptors in the ALI/ARDS. Regarding sickness behavior, animals received CPZ administration 30 minutes before application of LPS 200 μg/kg, and after 2 hours were submitted to the behavioral tests and blood and tissues collection. The administration of blocker attenuated the anxious and depressive-like effects, the increased body temperature and the c-fos expression in some brain areas induced by LPS. However, CPZ did not promote changes in mobility, food intake, weight gain, plasma levels of cytokines and protein expression in the hippocampus and hypothalamus. These results suggest the involvement of TRPV1 receptors in the modulation of sickness behavior, in regulating body temperature and respiratory mechanics after immune challenge.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
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Rossato, Mateus Fortes. "Eriodictiol: um flavonóide antagonista do receptor trpv1 com atividade antioxidante." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/11134.
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Conselho Nacional de Desenvolvimento Científico e TecnológicoThe transient receptor potential vanilloid 1 (TRPV1) is a calcium permeable channel responsible for the transduction and modulation of acute and chronic pain signaling, being a potential target for treatment of different pain disorders. In spite of that, AMG517, a TRPV1 antagonist, presents several clinical limitations, such as the development of severe hypertermia. The aim of this study was to investigate the possible interaction of the flavonoid eriodictyol with the TRPV1 receptor and its putative antinociceptive and hyperthermic effect. Eriodictyol was able to displace the [3H]-resiniferatoxin binding (IC50 = 47 (21 - 119) nM) and to inhibit the calcium influx mediated by capsaicin (IC50 = 44 (16 125) nM), suggesting that eriodictyol acts as a TRPV1 antagonist. Moreover, eriodictyol induces antinociception in the intraplantar capsaicin test, with maximal effect of 49±10 and 64±4% of inhibition for oral (ED50 = 2 (1-5) mg/kg) and intrathecal (ED50 = 2 (1-3) nmol/site) routes, respectively. Concomitantly, eriodictyol did not induce any alteration on body temperature or locomotor activity. Orally administered eriodictyol (4.5 mg/kg) prevented the nociception induced by intrathecal injection of capsaicin (72±6% of inhibition), the non-protein thiol loss and the 3-nitrotyronise (3-NT) formation induced by capsaicin in spinal cord. Eriodictyol (4.5 mg/kg, p.o.) also reduced the thermal hyperalgesia (100% of inhibition) and mechanical allodynia (62±9% of inhibition) elicited by complete Freund s adjuvant (CFA) paw injection. In conclusion, Eriodictyol acts as an antagonist of TRPV1 receptor and an antioxidant, inducing antinociception without some side effects and limitations expected for TRPV1 antagonists, as hyperthermia.
O receptor de potencial transiente vanilóide 1 (TRPV1) é um canal iônico permeável a cátions ativado por uma série de estímulos nocivos, como calor, acidificação e agentes irritantes como a capsaicina. Este receptor é responsável pela detecção e transmissão da dor aguda e crônica. Devido a isso, substâncias que modulem a atividade deste receptor apresentam um potencial clínico para o tratamento da dor. Assim, este trabalho objetiva a possível interação do flavonóide eriodictiol com o receptor TRPV1. Inicialmente, observamos que o eriodictiol foi capaz de deslocar o radioligante [3H]-resiniferatoxina, em ensaio de união específica, do receptor TRPV1 com uma concentração inibitória 50% (IC50) de 46.9 (20.70 - 118.9) nM. Ao mesmo tempo, o eriodictiol também inibiu o influxo de cálcio estimulado por capsaicina com IC50 de 44,4 (15,6 125,1) nM, sugerindo que este aja como um antagonista do receptor. Além disso, também observamos que o eriodictiol induz antinocicepção no teste da capsaicina intraplantar com efeito máximo de 49,0±10.5 e 63,9±4.0 % de inibição máxima para o tratamento oral e intratecal, respectivamente, e com uma dose efetiva 50% (DE50) de 2,4 (1,0 5,5) mg/kg 2,2 (1,6 2,9) nmol/site, respectivamente. Além disso, não observamos alterações na atividade locomotora ou temperatura corporal dos animais. A administração oral de eriodictiol também foi capaz de prevenir a nocicepção induzida por capsaicina intratecal (71,7±5,7 % de inibição). Ao mesmo tempo, o eriodictiol também aboliu a hiperalgesia térmica e reduziu a alodínia mecânica (62,4±9,2 %) induzidas por adjuvante completo de Freund. Da mesma forma, o eriodictiol também preveniu totalmente a diminuição de tiois não protéicos e formação de 3-nitrotirosina (3-NT) espinhais induzidas por capsaicina, ao passo que apresentou atividade antioxidante direta no texto de neutralização do radical ABTS. Em conclusão, nossos resultados mostram que o eriodictiol age como um antagonista do receptor TRPV1, com atividade antioxidante, induzindo antinocicepção sem os efeitos colaterais e limitações esperados para antagonistas do receptor TRPV1.
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Kiasalary, Reineh Zahra. "Anatomical and functional studies on TRPV1- expressing primary sensory neurons." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420426.
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Sadofsky, Laura Rachel. "Molecular pharmacology of the capsaicin receptor (TRPV1) in the airways." Thesis, University of Hull, 2005. http://hydra.hull.ac.uk/resources/hull:8630.
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The capsaicin receptor (vanilloid receptor I, transient receptor potential vanilloid 1 or TRPV I) is a member of the transient receptor potential (TRP) family of proteins. This cation channel is sensitive to a range of inflammatory mediators such as some lipoxygenase products, as well as the tussive agents capsaicin, resiniferatoxin and protons. It has been proposed that TRPV I is a cough receptor and may be important in airways inflammation. Rat TRPVI (rTRPVI) and human TRPVI (hTRPVl) permanently expressing cell lines were generated and successfully characterised by agonist triggered changes in intracellular calcium levels. Thapsigargin and/or removal of extracellular calcium revealed that, both rTRPVI and hTRPVI are not only expressed on the cell surface but on thapsigargin sensitive and insensitive intracellular stores respectively. Citric acid, an agent routinely used in the clinic for inhalation cough challenges, was investigated for its ability to activate TRPVl permanently expressed in a cell line. rTRPV I was activated by citric acid in a concentration and pH dependent manner. Citric acid activation of TRPVI was inhibited by iodoresiniferatoxin but not capsazepine. Mutation of the TRPVI putative proton binding site (E648 to A648) abolished citric acid activation of the channel without reducing the capsaicin evoked response. Thus, citric acid activates rTRPV I by a proton dependent mechanism. The role of N-linked glycosylation and sialylation on rTRPVI and hTRPVI was investigated. Treatment of rTRPVl with neuraminidase or tunicamycin dramatically reduced the channels' maximal responses to capsaicin. In addition mutation of the rTRPVI N-linked glycosylation site (N604 to Q604) or expression ofrTRPVI in the glycosylation mutant cell line, Lec2, also resulted in a striking reduction in the receptors' maximal calcium response to capsaicin. Flow cytometry data indicated that these differences in TRPVI function were unlikely to be linked to differences in receptor cell surface expression. Human TRPV I also displayed significant reductions in responsiveness to capsaicin following either neuraminidase or tunicamycin treatment. Thus, receptor sialylation regulates TRPVI activation by capsaicin. Finally, TRPVI expression on human primary bronchial fibroblasts (HPBF) was investigated. Negligible endogenous TRPVI expression was detected in HPBF. Interestingly, the inflammatory mediators tumour necrosis factor (TNF-a), lipopolysaccharide (LPS) and interleukin Ia (IL-Ia) all induced TRPVI expression in HPBF, as assessed by RT-PCR, flow cytometry and calcium signalling. TRPVI functional expression was observed as early as 6 hrs (for TNF-a) post challenge and remained elevated upto the final time point tested (96 hrs for IL-Ia). Thus, TRPVI may play an important role in the inflammatory process. In conclusion, TRPV I may play an important role in conditions where cough and inflammation have been implicated.
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Bhattacharjee, Anupam. "The biophysics and pharmacology of native and recombinant TRPV1 receptors." Thesis, King's College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409218.
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Paule, Cleoper. "Molecular bases underlying the sensitivity of the capsaicin receptor TRPV1." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6144.
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Individual human beings report highly variable pain experiences following exposure to the same noxious stimulus, including noxious heat. A series of missense single nucleotide polymorphisms (SNPs) have been found in the human noxious heat transducer, transient receptor potential vanilloid type 1 ion channel (hTRPV1), which responds to, exogenous, and endogenous, vanilloids, protons, and depolarisation. The aim of this project was to examine the effect of SNPs on the sensitivity of hTRPV1 to certain activators. The three most frequently occurring SNPs (I315M, T469I, V585I) were used to generate 4 haplotypes: hTRPV1112 (V585I); hTRPV1121 (T469I); hTRPV1211 (I315M); and hTRPV1222 (I315M, T469I, V585I). The responses of these haplotypes to these activators were compared to the responses of the “wild type” hTRPV1 (hTRPV1111, I315, T469, V585) using whole-cell patch-clamp recordings from HEK293 cells which transiently-expressed the relevant ion channels. Site-directed mutagenesis was used to confirm the role of the SNPs in altering the sensitivity of hTRPV1 to the activators applied. In addition, in control experiments, several important collateral issues were investigated, namely: (a) the effect of the solvent, dimethyl sulphoxide (DMSO), on untransfected, and transfected, cells, respectively; and (b) the extent to which acid-sensing ion channels, constitutively-expressed by HEK293 cells, compromised the assessment of the proton-evoked responses of hTRPV1. The techniques employed included: the co-transfection of the cells with vector carrying the coding region of the green fluorescent protein (GFP) gene; the reverse transcriptase polymerase chain reaction; immunocytochemistry; the cobalt uptake assay; and whole-cell patch-clamp recordings. The pharmacological and biophysical properties of the DMSO-evoked, and capsaicin-evoked, responses were similar. Furthermore, DMSO desensitised TRPV1. Acid-sensing ion channels were sensitive to the diuretic, amiloride (30μM). However, amiloride increased hTRPV1-mediated responses evoked by noxious heat but not capsaicin. hTRPV1222 showed a higher sensitivity than hTRPV1111 to capsaicin, and heat. Thus, when capsaicin was applied, the EC50 of hTRPV1111 and hTRPV1222 was 817 nM and 89 nM, respectively. The activation thresholds when heat was applied to hTRPV1111 and hTRPV1222 were 44.5±0.31 oC, and 42.3±045 oC, respectively). However, hTRPV1111 was more sensitive to depolarisation than hTRPV1222, with the V1/2 at 37oC for hTRPV1111 and hTRPV1222 being 42.3 mV and 83.3 mV, respectively. Furthermore, no differences were found between the proton-and anandamide- sensitivity of hTRPV1111 and hTRPV1222. The sensitivities of hTRPV1121 to heat and depolarization were similar to those of hTRPV1222, but different from those of hTRPV1111. Furthermore, the sensitivity of hTRPV1112 and hTRPV1211 were similar to that of hTRPV1111, but different from that of hTRPV1222 and hTRPV1121. Charge-neutralising and conserving mutations at position 469 produced clones with similar sensitivities to hTRPV1121 and hTRPV1111, respectively. The studies undertaken established, first, that DMSO is able to activate TRPV1. Second, the non-synonymous SNP at position 469 in hTRPV1 alters the sensitivity of the ion channel to vanilloids, heat, and depolarisation. These findings suggest that missense SNPs in hTRPV1 may contribute to the development of different pain experience in humans in response to the same noxious stimulus. Accordingly, regard must be had to SNPs found in hTRPV1 when attempting to develop analgesics for pain which depends on TRPV1 activation and in treating that pain. Finally, the finding that the T469I mutation increased the sensitivity of the molecule to heat, but reduced its sensitivity to depolarisation, suggests that the various sensors in TRPV1 may be coupled allosterically rather than directly.
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Saunders, Cecil James. "The respiratory response of Trpv1 knockout mice to trigeminal irritants." Winston-Salem, NC : Wake Forest University, 2008. http://dspace.zsr.wfu.edu/jspui/handle/10339/37483.
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Tessier, Nolwenn. "Rôle du canal calcique TRPV1 dans l’ischémie-reperfusion du myocarde." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1165.
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Au cours de l’infarctus du myocarde, aussi bien l’ischémie que la reperfusion (I/R) entrainent des dégâts irréversibles au sein du myocarde. Parmi ces lésions cellulaires, la dérégulation de l’homéostasie calcique mène à la mort cellulaire. Afin d’augmenter la récupération suite à un épisode d’I/R, le « remote », pré- et post-conditionnement ont été montré comme cardioprotecteur. En particulier, certaines stratégies basées sur des molécules pharmacologiques modulant les canaux TRPV1 (Transient Receptor Vanilloid 1) ont été utilisées. Le but de cette étude est de comprendre le rôle de TRPV1 dans la cardioprotection. Nous avons récemment montré que TRPV1 est exprimé et est fonctionnel dans des cardiomyocytes adultes de souris. En revanche, afin d’utiliser des sondes génétiques, un modèle alternatif aux cardiomyocytes a été utilisé dans cette étude : la lignée cellulaire de cardiomyoblastes de rats.Grâce à des techniques de Western blot et d’imagerie confocale, nous avons d’abord montré que TRPV1 est exprimé dans les H9C2 et semble être localisé à la membrane du réticulum endoplasmique (RE). Puis, nous avons démontré grâce à des techniques d’imagerie calcique dans le cytoplasme et le réticulum (Fura2-AM et ErGAP1 respectivement) que TRPV1 est un canal de fuite calcique fonctionnel RE. Comme la synthèse d’ATP et le métabolisme cellulaire sont dépendants des échanges de calcium (Ca2+) entre le RE et la mitochondrie, nous avons analysé le rôle de TRPV1 en mesurant le Ca2+ mitochondrial avec la sonde R-GECO. Nous avons montré que la modulation pharmacologique de TRPV1 augmente à la fois les contenus en Ca2+ cytoplasmique et mitochondrial d’au moins 20%. Enfin, nous avons effectué des séquences d’hypoxie-reoxygenation et nous avons évalué la mort cellulaire par cytométrie en flux. Nous avons montré que l’activation de TRPV1 a des effets hétérogènes sur la viabilité cellulaire alors que l’inhibition de TRPV1 augmente systématiquement la survie cellulaire, d’au moins 22%. Des évènements de Ca2+ précis et spatiotemporel du RE à la mitochondrie sont nécessaires pour initier ou réguler des multitudes de processus tels que la balance entre la mort cellulaire et la survie cellulaire. Dans cette étude, nous avons montré que TRPV1 pouvait être un de ces canaux impliqués dans cet échange de Ca2+ entre le RE et la mitochondrie et que les H9C2 sont un modèle viable pour évaluer le rôle de TRPV1 dans les flux calciques au cours de l’ischémie-reperfusionDuring myocardial infarction, both I/R cause irreversible myocardial injuries. Among the cellular damages, calcium dysregulation occurs leading to cell death. To improve the recovery from I/R episodes, remote, pre- and post-conditioning are recognized to be cardioprotective. In particular, some strategies based on molecules acting on the TRPV1 channels have been used. The aim of our work is to better understand TRPV1 role in cardioprotection. We have recently demonstrated that TRPV1 is expressed and functional in adult mouse cardiomyocytes. In order to perform live imaging with genetic probes, an alternative model to cardiomyocytes was used in the present work: H9C2 cells. Thanks to Western blot and confocal microscopy, we first showed that TRPV1 is expressed in H9C2 and seems to be localized at endoplasmic reticular (ER) plasma membrane. Secondly, we demonstrated that TRPV1 is a functional ER Ca2+ leak channel via cytoplasmic and reticular Ca2+ imaging (respectively with Fura-2 and ErGAP1). As ATP synthesis and cell fate are dependent of Ca2+ exchanges between ER and mitochondria, we have analyzed the role of TRPV1 in the mitochondrial [Ca2+] using R-GECO probe. We observed that pharmacological TRPV1 modulation increases both cytosolic and mitochondrial Ca2+ contents by at least 20%. Finally, we performed hypoxia-reoxygenation sequences and we evaluated cell death by flow cytometry. We showed that TRPV1 activation has heterogeneous effects on cell viability, whereas TRPV1 inhibition always improves cell survival (at least by 22%). Precise and spatiotemporal Ca2+ release events from ER to mitochondria are required to initiate or to regulate many processes like the balance between cell death/cell survival. In the present study, we show that TRPV1 could be one of the channels involved in Ca2+ exchanges between ER and mitochondria, and that H9C2 is a valuable model to evaluate the role of TRPV1 in Ca2+ fluxes during I/R
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Hua, Pierce. "Characterization of a novel pre-pore loop antibody against rat TRPV1." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111948.
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Splice variants of the transient receptor potential vanilloid type-1 (TRPV1) channel appear to be involved in the physiological detection of extracellular fluid (ECF) osmolality in the supraoptic nucleus (SON) and organum vasculosum lamina terminalis (OVLT). It remains to be determined whether these splice variants are directly involved as pore-forming proteins in the osmosensory transduction complex. Since these TRPV1 splice variants are not sensitive to capsaicin antagonists, such as capsazepine (Sharif Naeini et al., 2007), novel tools that specifically interfere with ion permeation through TRPV1 are required for functional studies on the involvement of this channel. In this study, we developed rabbit polyclonal antibodies targeting specifically the extracellular pre-pore loop region of rat TRPV1 (PH-4281). Histological results showed that PH-4281 is specific to rat TRPV1 and TRPV1 expression is found in regions that are known to be osmosensitive. PH-4281 could be used as a specific tool to study the osmosensory transduction complex.
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Sharif, Naeini Reza. "Contribution of the Trpv1 gene to the physiology of supraoptic neurons." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111867.
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The release of vasopressin (VP) from magnocellular neurosecretory cells (MNCs) of the supraoptic (SON) and paraventricular (PVN) nuclei is essential to hydromineral homeostasis. This release is controlled by several physiological stimuli, including changes in the osmotic pressure of the extracellular fluid, and in core body temperature. The osmotic control of VP release is mediated by specific and highly sensitive 'osmoreceptors'. Indeed, VP-releasing neurons in the SON are directly osmosensitive, and this osmosensitivity is mediated by stretch-inhibited cation channels. The molecular identity of these channels, however, remains unknown. The thermal control of VP release, on the other hand, is largely unexplained. In this thesis, we demonstrate that the mouse SON is a valid model for investigating the molecular basis of osmotransduction. We show that hyperosmotically-induced increases in membrane conductance are blocked by ruthenium red (RR), a non selective blocker of TRPV channels. In addition, SON neurons were found to express an N-terminal splice variant of TRPV1, but not full-length TRPV1. Unlike their wild-type counterparts, SON neurons in Trpv1 knockout (Trpv1-/-) mice could not generate RR-sensitive increases in membrane conductance and depolarizing potentials in response to hyperosmotic stimulation. Moreover, Trpv1-/-mice showed a pronounced serum hyperosmolality under basal conditions and severely compromised VP responses to osmotic stimulation in vivo. These results suggest that the Trpv1 gene may encode a central component of the osmoreceptor. Furthermore, we demonstrate that VP neurons are intrinsically thermosensitive. In these neurons, thermal stimuli spanning core body temperatures activate a RR-sensitive non selective cation current. Interestingly, VP neurons isolated from Trpv1 -/-mice are significantly less thermosensitive. These results suggest that channels encoded by the Trpv1 gene can confer thermosensitivity in the physiological range. Overall, these data suggest that products of the Trpv1 gene in VP neurons may represent a molecular point of convergence for the detection of osmotic and thermal stimuli.
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Kasper, Christian [Verfasser]. "Die Modulation des TRPV1 Kanals durch das Adapterprotein ARMS / Christian Kasper." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2018. http://d-nb.info/1160514763/34.
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Bonacin, Yuri da Silva. "Expressão e quantificação de receptores vanilóides TRPV1 na dermatite digital bovina /." Jaboticabal, 2017. http://hdl.handle.net/11449/150352.
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Orientador: José Antonio MarquesCoorientador: Sérgio Britto Garcia
Banca: Deborah Penteado Martins Dias
Banca: Paulo Aléscio Canola
Resumo: A Dermatite Digital Bovina (DDB) constitui uma das principais causas de graus elevados de claudicação em bovinos leiteiros, em função da dor que estes animais aparentam frente ao estímulo nocioceptivo. A hiperalgesia em alguns casos de dor crônica está relacionada à expressão exacerbada de fibras dos receptores vaniloides TRPV1, podendo haver forte correlação com casos crônicos da DDB. No presente estudo foram utilizados 15 bovinos, fêmeas, da raça Holandesa Preto e Branco, com idades de 2 a 7 anos, em lactação com pico médio de 47,85 L, mantidos em regime "free-stall". Durante o casqueamento realizado na propriedade, as lesões da DDB foram identificadas e divididas em quatro grupos, referentes aos quatro estágios da doença (inicial M1, clássico M2, intermediário M3 e crônico M4). Foram coletadas biópsias por meio de "punch" cutâneo (4mm). Além das lesões foram coletadas amostras de pele sadia de cada animal. Priori às biopsias realizou-se a dimensionamento das lesões, para média comparativa entre os estágios. Os fatores predisponentes ao aparecimento de lesões (idade, número de partos e pico de lactação) foram considerados. As biopsias foram processadas em laboratório e colocadas frente à reação imunológica com anticorpos anti-TRPV1 (Chemicon -USA). Posteriormente as fibras imuno-marcadas nos quatro grupos e pele sadia foram contabilizadas e comparadas. As dimensões das lesões foram analisadas pelo método estatístico descritivo e possuíam média de comprimento e largura no es... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The Bovine Digital Dermatitis (BDD) is one of the main cause on high claudication levels at the dairy cattle, as a result of the pain that appear in those animal front of the nociceptive stimulus. Hyperalgesia in some chronic pain cases is related to the exacerbated expression of vanyloid TRPV1 fibers, and may have a hole on the chronic cases of BDD. In the present study, 15 Black and White Holstein cow was used, aged 2 to 7 years old, during lactation with mean peak of 47.85L, kept in the free-stall under the same diet. BDD lesions were identified and divided into 4 stages of the disease (initial M1, classic M2, intermediate M3 and chronic4), which skin are collected by dermal punch (4mm). In addition to the lesions, healthy skin samples were collected from each animal. Prior to the biopsies, the lesion dimensions were taken, for comparative average between the stages. Predisposing factors to the lesions appearance (age, number of births and lactation peak) were considered. The biopsies were processed at the laboratory and reacted with anti-TRPV1 antibodies (Chemicon -USA). The immuno-marked fibers in the four groups and healthy skin were counted and compared. The lesion dimensions were analyzed by descriptive statistical method and had a M1 mean length/ width on M1 of 5,60mm±3,20 x 4,4±1,34mm, M2 of 12,60±6,46mm x 14,4±8,87mm, M3 of 21,60±3,36mm x 17,20±6,61mm and M4 of 21,60±3,36mm x 24,57±7,32mm. The thickness mean value in M1 of 1.80 ± 1.09mm, M2 of 6.20 ± 2.16mm, M3 of 7.40 ± 6.54mm and M4 of 8.85 ± 4.14mm. The predisposing factors results were analyzed separately with the number of lesions by Pearson Correlation statistic method (p <0.05). There was difference between more lesion and birth numbers. TPV1 fiber counts were analyzed by logarithmic scale (p <0.05), with a significant difference between the M4 group (chronic stage of DDB) and the other groups.
Mestre
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Mak, Stephanie Wai Yin. "Modulation of temperature sensitive ion channels TRPV1 and TRPM8 by Bradykinin." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611520.
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Santos, Fabio Martinez dos. "Mobilização neural: avaliação molecular e comportamental em ratos Wistar após indução de dor neuropática." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/42/42131/tde-05102015-150313/.
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A técnica de Mobilização Neural (MOB) é um método não invasivo que demonstrou tanto na pesquisa básica, como na pesquisa clinica ser eficaz na redução da sensibilidade à dor. O presente, estudo visa examinar os efeitos da MOB na disfunção locomotora, na força muscular, nas alterações morfológicas no nervo isquiático e nas alterações moleculares induzida pela constrição crônica (CCI) do nervo isquiático de ratos Wistar. Para analisar a disfunção locomotora utilizamos o índice funcional do nervo Isquiático (IFC). Para analisar a força muscular, o sistema Biopac System. A ultraestrutura do nervo foi analisada pela técnica de microscopia eletrônica de transmissão e as alterações moleculares por meio de ensaios de Western blot. Ao finalizarmos os tratamentos com MOB os animais foram eutanasiados e os tecidos como, nervo isquiático, gânglios das raizes posteriores (DRG L4-L6) e Susbtância Cinzenta Periaquedutal (PAG) foram retirados. Os DRG´s foram processados pela técnica de Western Blot para a detecção da substância P (SP), receptor de potencial transitório vanilóide tipo I (TRPV1) e receptores opióides dos tipos µ (MOR), δ (DOR) e k (KOR). Com relação a PAG, analisamos somente os receptores opióides por Western Blot. Nossos resultados demonstraram uma reverção da disfunção locomotora induzida pela CCI após a MOB e aumentou 172% a força do músculo tibial anterior nos animais tratados quando comparado com os animais do grupo CCI. Nossos estudos sobre a ultraestrutura do nervo isquiático demonstraram intenso processo de degeneração Waleriana após a CCI e regeneração após a MOB. Podemos sugerir um papel importante da MOB na modulação da expressão da SP e do TRPV 1. Sobre os receptores DOR e KOR no DRG, não encontramos alterações estatísticas entre os grupos, mas observamos um aumento da expressão de MOR após a MOB. Na PAG, nós observamos uma diminuição de DOR e KOR no grupo CCI e aumento após a MOB. Por outro lado, não encontramos alterações estatíticas para o receptor MOR. Baseado nestes achados, podemos sugerir que a MOB reverte a disfunção locomotora, aumenta a força muscular, induz a regeneração do nervo isquiático, modula a SP e TRPV 1 e aumentou a expressão de MOR no DRG´s. Sugerimos ainda que, a analsegia induzida pela técnica de MOB possa ter um envolvimento também com o sistema inibitório descendente de dor resultando na inibição da transmissão do estímulo nociceptivo aferente e assim, diminuindo a dor neuropática devido influência da MOB sobre os opióides na PAG.Neural mobilization technique (MOB) is a noninvasive method that demonstrated to be effective in reducing pain sensitivity in both clinical and research study. The present study aims to examine the effects of MOB in locomotors dysfunction, muscle strength, morphological changes in sciatic nerve and molecular changes induced by chronic constriction (CCI) of the sciatic nerve in Wistar rats. To analyze locomotors dysfunction we used the Sciatic nerve functional index (SFI). To analyze muscle strength, was used Biopac System. The nerve morphology was analyzed using electron microscopy and molecular changes through western blot assays. After MOB treatments, animals were euthanized and tissues such as, sciatic nerve, the posterior root ganglions (DRG L4-L6) and substance periaqueductal gray (PAG) were removed. The DRG were processed by western blot for detection of substance P (SP), transient receptor potential vanilloid type I (TRPV1) and opioids receptors (MOR, DOR, KOR). Regarding PAG, we analyze only opioids receptors. Our results demonstrated a full reversal of locomotors dysfunction-induced by CCI after MOB treatment and an increase of 172% on maximal tetanic muscle strength in animals treated with MOB when compared to the CCI group. Our studies on photomicrography of sciatic nerve showed an intense Wallerian degeneration process in CCI animals and an intense regeneration of myelinated fibers. In western blot assays, we identified, in DRG, an increase of SP and TRPV1 expression after CCI and a decrease of optical density after MOB treatment. Regarding opioid receptor, we did not identify statistical changes on DOR and KOR in DRG, but we observed an increased expression of MOR in CCI after MOB treatment group. In PAG analyses, we observed a decrease in DOR and KOR expression after MOB treatment when compare with CCI animals. On the other hand, we did not identify any changes on MOR receptor. Based on our findings, we suggest that treatment with neural mobilization technique it is able to reverses the locomotors dysfunction and increases maximum tetanic force of the tibialis anterior muscle after CCI. Furthermore, the same treatment was also able to induce a severe regeneration in the sciatic nerve after treatment. Still, we can suggest an important role of MOB in modulating SP and TRPV 1 expression. We suggest that antinociceptive effect induced by MOB technique can also be involved with descending pain inhibitory system resulting in inhibition of the transmission of afferent nociceptive stimulus and thereby reducing neuropathic pain because of the influence of MOB opioids in the PAG.
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JÃnior, Roberto CÃsar Pereira Lima. "Antinociceptive effect of the mixture of pentacyclic triterpenes alpha- and beta- amyrin in models of visceral nociception in mice." Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=4.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorProtium heptaphyllum March (Burseraceae), a medicinal plant commonly found in the Amazon and in the Northeast regions of Brazil, releases an oil-resin rich in pentacyclic triterpenes, such as the binary mixture of alpha- and beta- amyrin, that manifests antiinflamatory, antinociceptive and gastroprotective properties. This work was aimed to evaluate the antinociceptive effect of the alpha- and beta- amyrin mixture in the cyclophosphamide (400 mg/kg), acetic acid (0,6%, 10mL/kg, i.p.) and mustard oil-induced visceral nociception models in mice and to establish the likely mechanism(s) of action. In the cyclophosphamide-induced visceral pain model, pretreatment of mice with triterpene mixture at the oral doses of 10, 30 and 100 mg/kg significantly reduced (p<0.001) the pain-related behavioral expression time (59,7; 75,5 e 92,3%, respectively, versus the cyclophosphamide-treated group 12,25 +/- 2,98 min) in a dose-dependent manner. Suppression of visceral painârelated behaviors was also evidenced to the triterpenoid mixture (10 mg/kg) in the intraperitoneal acetic acid- and intracolonically injected mustard oil-induced test models of visceral nociception 50,4% e 61,1%, respectively compared to the acetic acid-treated group (42,33 +/- 3,78 abdominal constrictions/20 min) in the writhing test and to the control in the mustard oil (0,75%, 50 mcL/animal) experiment (39,28 +/- 3,26). In these tests, the maximal suppression of visceral pain was observed at 10 mg/kg. The possible mechanisms involved in the antinociceptive action of alpha- and beta- amyrin (10 mg/kg) were analyzed in the mustard oil-induced visceral pain model. In the evaluation of the opioid receptor involvement, both the triterpene mixture and morphine (5 mg/kg, s.c.) effectively inhibited (p<0.001) the number of pain-related behaviors, which could be significantly reversed by pretreatment of animals with an opioid antagonist naloxona (2mg/kg, i.p.), suggesting the opioid participation in the alpha- and beta- amyrin mechanism of action. In the study of the alpha2-adrenoreceptor involvement, the triterpene mixture as well as clonidine (0.1 mg/kg, i.p.), a known alpha2 agonist, inhibited (p<0.001) the nociceptive behavioral expression. However, when the animals were pretreated with yohimbine, an alpha2-adrenoreceptor antagonist, only the inhibitory action of clonidine was reversed, suggesting the non-participation of alpha2- adrenoreceptor in the antinociceptive action of alpha- and beta- amyrin. In the evaluation of TRPV1 receptor involvement, mice pretreated with either the alpha- and beta- amyrin, ruthenium red, a TRPV1 non-competitive antagonist, (3 mg/kg, s.c.) or their combination induced a significant and similar inhibition (p<0.001) of the number of nociceptive behaviors. The degree of inhibition with no potentiation or antagonism suggests that alpha- and beta- amyrin may act as a TRPV1 non-competitive antagonist, like ruthenium red. In order to evaluate a possible sedative, motor impairment and motor incoordination effects related to alpha- and beta- amyrin, the penthobarbitone-induced sleeping time, open-field and rota-rod tests were performanced, respectively. The data indicated that the treatment of animals with the alpha- and beta- amyrin mixture (10 mg/kg) was unable to cause sedation, motor impairment or motor incoordination effects (p>0.05), being even able to reverse (p<0.05) a mustard oil-induced motor impairment in the open field test. The results taken together strongly suggest the therapeutic potential of alpha- and beta- amyrin in oblitering visceral nociception through the mechanisms that involve the opioids and TRPV1 receptors.
O Protium heptaphyllum March. (Burseraceae), uma planta medicinal encontrada na regiÃo AmazÃnica e Nordeste do Brasil, produz uma resina rica em triterpenos pentacÃclicos, como a mistura binÃria alpha- e beta- amirina, que apresentam atividade antiinflamatÃria, gastroprotetora e antinociceptiva. Este trabalho objetivou investigar a atividade antinociceptiva de alpha- e beta- amirina em modelos de dor visceral induzida por ciclofosfamida, Ãcido acÃtico e Ãleo de mostrada em camundongos, alÃm dos possÃveis mecanismos de aÃÃo envolvidos. No modelo de nocicepÃÃo visceral induzida por ciclofosfamida (400 mg/kg, i.p.), a mistura de triterpenos nas doses de 10, 30 e 100 mg/kg, v.o., reduziu (p<0,001) de forma dose-dependente o tempo de expressÃo dos comportamentos relacionados à dor visceral (59,7; 75,5 e 92,3%, respectivamente, versus o controle ciclofosfamida 12,25 +/- 2,98 min). Realizou-se o estudo nos modelos de contorÃÃes abdominais induzidas por Ãcido acÃtico (0,6%, 10mL/kg, i.p.) e dor visceral induzida por Ãleo de mostarda (0,75%, 50 mcL/animal) intracolÃnico. Os resultados indicaram uma inibiÃÃo do nÃmero de comportamentos de dor expressos pelos animais, sendo o maior nÃvel de inibiÃÃo (p<0,001) encontrado na dose de 10 mg/kg da alpha- e beta- amirina 50,4% e 61,1% comparados respectivamente ao controle Ãcido acÃtico (42,33 +/- 3,78 contorÃÃes/20min) no teste de contorÃÃes abdominais e ao controle Ãleo de mostarda (39,28 +/- 3,26) no modelo de dor visceral por Ãleo de mostarda. Para o estudo do possÃvel mecanismo de aÃÃo de alpha- e beta- amirina foi utilizada a dose de 10 mg/kg da mistura de triterpenos no modelo de nocicepÃÃo por Ãleo de mostarda. Na avaliaÃÃo da participaÃÃo do sistema opiÃide, a mistura dos triterpenos e a morfina (5 mg/kg, s.c.) inibiram significativamente (p<0,001) o nÃmero de comportamentos de dor expressos, havendo uma reversÃo da antinocicepÃÃo (p<0,05) quando prÃ-tratados com naloxona (2 mg/kg, i.p.), sugerindo a participaÃÃo opiÃide no mecanismo da alpha- e beta- amirina. No estudo do envolvimento do sistema adrenÃrgico, a mistura de triterpenos e a clonidina (0,1 mg/kg, i.p.), um agonista alpha2-adrenÃrgico, inibiram (p<0,001) a expressÃo dos comportamentos nociceptivos. PorÃm, com o prÃ-tratamento com ioimbina, um antagonista alpha2, houve reversÃo (p<0,05) da antinocicepÃÃo induzida pela clonidina, mas nÃo da alpha- e beta- amirina, sugerindo o nÃo envolvimento deste receptor na antinocicepÃÃo da mistura de triterpenos. No estudo do envolvimento do receptor TRPV1, o prÃ-tratamento dos animais com alpha- e beta- amirina, vermelho de rutÃnio (3 mg/kg, s.c.), um antagonista nÃo competitivo deste receptor, ou com a combinaÃÃo da mistura de triterpenos com vermelho de rutÃnio, houve uma inibiÃÃo (p<0,001) semelhante, para todos os tratamentos, dos comportamentos de dor. A nÃo potencializaÃÃo, ou antagonismo, do efeito antinociceptivo de alpha- e beta- amirina pelo vermelho de rutÃnio sugere que a mistura atue como um antagonista nÃo-competitivo TRPV1. Para avaliar a existÃncia de um efeito sedativo, de um impedimento locomotor ou de uma incoordenaÃÃo motora, foram utilizados os testes do tempo de sono induzido por pentobarbital, teste do campo aberto e o teste do rota rod, respectivamente. Os dados indicaram que o tratamento com a mistura de triterpenos (10 mg/kg) nÃo induziu (p>0,05) sedaÃÃo, impedimento locomotor ou incoordenaÃÃo motora nos animais, sendo ainda capaz de reverter (p<0,05) o impedimento locomotor induzido pelo Ãleo de mostarda no teste do campo aberto. Em conjunto os dados revelaram a efetividade da mistura de alpha- e beta- amirina em modelos de nocicepÃÃo visceral possivelmente envolvendo receptores opiÃides e TRPV1.
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Dias, MarÃlia Leite. "Atividade antinociceptiva da riparina IV: participaÃÃo dos receptores TRPV1, TRPM8, receptores glutamatÃrgicos e do Ãxido nÃtrico." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8632.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorA Riparina IV, uma alcamida sintetizada de Aniba riparia, foi testada em modelos animais padronizados de dor, bem como os possÃveis mecanismos de aÃÃo envolvidos. Foram utilizados camundongos Swiss (20-30g), e a Riparina IV foi administrada de forma aguda em todos os testes, nas doses de 25 e 50 mg/kg, por via oral. Foram utilizados os testes de contorÃÃes abdominais induzidas por Ãcido acÃtico; placa quente; teste da formalina; hipernocicepÃÃo mecÃnica induzida pela carragenina; teste da nocicepÃÃo induzida por capsaicina, cinamaldeÃdo, mentol; teste da nocicepÃÃo induzida por glutamato, bem como em modelos comportamentais que permitam excluir a possibilidade de uma atividade relaxante muscular ou induzir resultados falso-positivos nos modelos anteriores, tais como testes do campo aberto e rota Rod. Os resultados demonstraram que a Riparina IV possui uma atividade antinociceptiva no modelo de nocicepÃÃo visceral induzida por Ãcido acÃtico. A Riparina IV nÃo demonstrou atividade no modelo de nocicepÃÃo tÃrmica da placa quente. O prÃ-tratamento com a Riparina IV reduziu significativamente a nocicepÃÃo inflamatÃria induzida pela segunda fase da formalina, porÃm nÃo alterou a nocicepÃÃo neurogÃnica induzida pela primeira fase do teste da formalina. Os animais prÃ-tratados com a Riparina IV tambÃm exibiram uma reduÃÃo significativa na hipernocicepÃÃo mecÃnica induzida pela carragenina. Em relaÃÃo à participaÃÃo dos receptores de potencial transitÃrio (TRP), a Riparina IV demonstrou atividade nos modelos de nocicepÃÃo induzida pela administraÃÃo de capsaicina e mentol, porÃm nÃo apresentou atividade na nocicepÃÃo induzida por cinamaldeÃdo. TambÃm reduziu a nocicepÃÃo induzida pela administraÃÃo intraplantar de glutamato. Para o estudo dos mecanismos de aÃÃo da Riparina IV foi utilizada somente a dose de 50 mg/kg da substÃncia. Na avaliaÃÃo da participaÃÃo dos canais de potÃssio ATP-dependentes, o prÃ-tratamento com glibenclamida nÃo foi capaz de reverter a aÃÃo antinociceptiva da Riparina IV, descartando-se o seu envolvimento; da mesma forma, o prÃ-tratamento com ioimbina, um antagonista α2-adrenÃrgico, e pCPA, um depletor das reservas de serotonina, tambÃm nÃo foram capazes de reverter tal aÃÃo, nÃo havendo envolvimento com o mecanismo de aÃÃo da Riparina IV. O prÃ-tratamento com L-arginina, um precursor do Ãxido nÃtrico, reverteu a aÃÃo antinociceptiva da Riparina IV, sugerindo, em parte, a participaÃÃo da via do Ãxido nÃtrico no seu mecanismo de aÃÃo. Os resultados mostraram que essa substÃncia nÃo alterou a atividade locomotora no teste do campo aberto, nem diminuiu o nÃmero de quedas no teste do rota Rod, descartando a possibilidade de haver sedaÃÃo ou incoordenaÃÃo motora por parte da Riparina IV. Em sÃntese, os resultados demonstraram que a Riparina IV possui uma atividade em modelos animais de nocicepÃÃo, possivelmente envolvendo os receptores TRPV1, TRPM8, glutamatÃrgicos e a via do Ãxido nÃtrico.
Riparin IV, an alkamide synthesized from Aniba riparia, was tested in standard animal models of pain, as well as the possible mechanisms of action involved. It was used Swiss mice (20-30g), and Riparin IV was administred acutely in all tests, at the doses of 25 and 50 mg/kg, by gavage. It was used the tests of abdominal writhing induced by acetic acid, hot plate test, formalin test, mechanical hypernociception induced by carrageenan, nociception test induced by capsaicin, cinnamaldehyde and menthol, nociception test induced by glutamate, as well as models of behavior that ruled out the possibility of a muscle relaxing activity or induce false-positive results in previous models, such as the open field test and the rota Rod test. The results showed that Riparin IV has an antinociceptive activity at the model of visceral nociception induced by acetic acid. Riparin IV did not show any activity at the hot plate thermal nociception model. Pretreatment with Riparin IV reduced significantly the inflammatory nociception induced at the second phase of formalin test, but did not alter the neurogenic nociception induced at the first phase of formalin test. The animals pretreated with Riparin IV also exhibited a significant reduction at the mechanical hypernociception induced by carrageenan. Related to the participation of the Transient Potential Receptors (TRP), Riparin IV showed an activity at the models of nociception induced by capsaicin and menthol, but did not show any activity at the nociception induced by cinnamaldehyde. Also reduced the nociception induced by administration of glutamate at the rind paw. To study the mechanisms of action of Riparin IV, it was used only the dose of 50 mg/kg of the substance. At the evaluation of participation of the ATP-dependent potassium channels, pretreatment with glibenclamide was not able to reverse the antinociceptive action of Riparin IV, discharging its involvment; at the same way, pretreatment with yohimbine, an a2-adrenergic antagonist, and pCPA, a depletor of the serotonin reservations, were not able of reverse such action, not having any involvement with the mechanism of action of Riparin IV. Pretreatment with L-arginine, a precursor of Nitric Oxide, reversed the antinociceptive action of Riparin IV, suggesting, in part, the participation of nitric oxide pathway at the mechanism of action. The results showed that this substance did not alter the locomotor activity at the open field test, neither diminished the number of falls at the rota Rod test, discharging the possibility of sedation or incoordination by Riparin IV. In summary, the results showed that Riparin IV has an action in animal models of nociception, possibly involving the receptors TRPV1, TRPM8, glutamatergic receptors and the nitric oxide pathway.
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Zhou, Bolu. "Activation Of Trpv1 Channel Contributes To Serotonin-Induced Constriction Of Mouse Facial Artery." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/754.
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Tight regulation of cephalic blood circulation is critical under normal physiological conditions, and dysregulation of blood flow to the head occurs in pathophysiological situations such as stroke and migraine headache. The facial artery is an extracranial artery which is one of branches from the external carotid artery territory and its extracranial position indicates its importance in regulating head hemodynamics. Transient receptor potential vanniloid type 1 (TRPV1) is a cation channel permeable to Ca2+ and Na+. Intracellular Ca2+ increase causes vasoconstriction. A previous study indicated the presence of TRPV1 in smooth muscle cells in the facial artery. Protein kinase C (PKC) is found to sensitize TRPV1 channels in neurons. Our lab's preliminary data suggested PKC modulates TRPV1 in the middle meningeal artery. Serotonin (5-HT) is an endogenous vasoconstrictor, and the 5-HT2 receptor is a Gq-protein-coupled receptor that activates PKC. In the present study, we found that 5-HT caused facial artery constriction. Thus, we studied whether TRPV1 channel acting as a Ca2+ entry channel is involved in 5-HT induced facial artery constriction. We used a pressurized arteriography technique to examine the artery diameter. The results indicate that 1) TRPV1 antagonist blunted 30 nM 5-HT-induced mouse facial artery constriction. 5-HT constriction on the facial artery from TRPV1 knock out mice was significantly blunted compared to the constriction on the facial artery from wild type mice; 2) PKC, which is a downstream signaling molecule of 5-HT2 receptor, is involved in capsaicin (TRPV1 agonist)-induced facial artery constriction; 3) 5-HT-induced facial artery constriction is mediated mostly by activation of 5-HT1 and 5-HT2 receptors; 4) 5-HT2 but not 5-HT1 receptor is involved in 5-HT-induced facial artery constriction via opening of TRPV1 channels; 5) PKC may be involved in 5-HT-induced facial artery constriction; 6) The L-type-voltage-dependent Ca2+ channel is involved in 5-HT-induced facial artery constriction. We conclude that activation of TRPV1 channel contributes to serotonin-induced 5-HT2 receptor-mediated constriction of the mouse facial artery.
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Vidal, Mosquera Miguel. "Chemical modulation of the nociceptive receptor TRPV1: Synthetic, biological and computational studies." Doctoral thesis, Universitat Ramon Llull, 2016. http://hdl.handle.net/10803/369846.
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El canal iònic Receptor Vanil·loide Tipus 1 (sigles en anglès TRPV1) es considera un important integrador de diverses senyals de dolor. D'entre tots els productes que interaccionen amb TRPV1, aquells que bloquegen el senyal doloros de forma no competitiva han atret l'interès dels investigadors que treballen en el camp. A partir de resultats prèviament obtinguts per a diversos peptoides que van mostrar activitat com antagonistes no competitius de TRPV1 i que van permetre proposar una senzilla hipòtesi farmacoforica que incloïa un grup catiònic i dos aromàtics idèntics, la present tesi es va centrar en el disseny i preparació de productes amb estructures més rígides, no peptoides, capaços d'interaccionar amb TRPV1 com bloquejadors no competitius. L'avaluació biològica d'una col·lecció de nous antagonistes i un estudi en profunditat in vitro i in vivo del compost més actiu van proporcionar informació sobre el mode d'acció d'aquests compostos.
Entre diferents alternatives considerades, l'esquelet d'1,3,5-triazina va ser seleccionat com el més adequat per albergar els requisits estructurals del farmacòfor proposat. Es van sintetitzar un total de 38 1,3,5-triazines-2,4,6-trisubstituidas amb estructures químicament diverses utilitzant un procediment prèviament optimitzat. Un estudi per RMN combinat amb càlculs teòrics va permetre determinar que moltes d'aquestes triazines presenten diferents confórmers en equilibri en solució, derivats de la rotació dels enllaços que uneixen les tres cadenes laterals a l'anell de triazina. Deu d'aquestes van resultar especialment actives, bloquejant el canal TRPV1 amb valors de IC50 en el rang submicromolar. D'entre les triazines sintetitzades destaca el compost 46 per la seva elevada potència (IC50 = 50 nM), trobant-se entre els bloquejadors de TRPV1 més potents descrits fins al moment. La triazina 46 presenta una activitat polimodal capaç d'inhibir l'activació de TRPV1 per capsaïcina i pH, una toxicitat reduïda tant en assajos in vitro com in vivo i actua de forma selectiva sobre TRPV1. Quant a la seva manera d'acció, 46 actua com un bloquejador de canal obert que s'uneix en una posició relativament profunda dins del porus aquós del canal.
S'han construït models 3D-QSAR emprant la tècnica CoMSIA, que correlacionen les propietats estructurals de la col·lecció de compostos sintetitzats amb la seva activitat. Aquests models donen suport a la hipòtesi inicial sobre els determinants estructurals de l'activitat antagonista TRPV1, i constitueixen una eina per a la predicció de l'activitat de nous compostos. Emprant aquests models es va predir una activitat en el rang baix micromolar per membres d'una família de analegs basats en un esquelet central de pirrolidina. La síntesi i avaluació de l'activitat antagonista de TRPV1 d'alguns d'aquests anàlegs va confirmar les prediccions, validant els models 3D-QSAR i establint aquests compostos com un interessant punt de partida per al desenvolupament d'una nova família d'antagonistes.El canal iónico Receptor Vanilloide Tipo 1 (siglas en ingles TRPV1) se considera un importante integrador de diversas señales de dolor. De entre todos los productos que interaccionan con TRPV1, aquellos que bloquean la señal dolorosa de forma no competitiva han atraído el interés de los investigadores que trabajan en el campo. A partir de resultados previamente obtenidos para varios peptoides que mostraron actividad como antagonistas no competitivos de TRPV1 y que permitieron proponer una sencilla hipótesis farmacoforica que incluía un grupo catiónico y dos aromáticos idénticos, la presente tesis se centró en el diseño y preparación de productos con estructuras más rígidas, no peptoides, capaces de interaccionar con TRPV1 como bloqueadores no competitivos. La evaluación biológica de una colección de nuevos antagonistas y un estudio en profundidad in vitro e in vivo del compuesto más activo proporcionaron información sobre el modo de acción de estos compuestos. Entre diferentes alternativas consideradas, el esqueleto de 1,3,5-triazina fue seleccionado como el más adecuado para albergar los requisitos estructurales del farmacóforo propuesto. Se sintetizaron un total de 38 1,3,5-triazinas-2,4,6-trisubstituidas con estructuras químicamente diversas utilizando un procedimiento previamente optimizado. Un estudio por RMN combinado con cálculos teóricos permitió determinar que muchas de estas triazinas presentan diferentes conformeros en equilibrio en solución, derivados de la rotación de los enlaces que unen las tres cadenas laterales al anillo de triazina. Diez de de ellas resultaron especialmente activas, bloqueando el canal TRPV1 con valores de IC50 en el rango submicromolar. De entre las triazinas sintetizadas destaca el compuesto 46 por su elevada potencia (IC50 = 50 nM), encontrandose entre los bloqueadores de TRPV1 más potentes descritos hasta el momento. La triazina 46 presenta una actividad polimodal capaz de inhibir la activacion de TRPV1 por capsaicina y pH, una toxicidad reducida tanto en ensayos in vitro como in vivo y actúa de forma selectiva sobre TRPV1. En cuanto a su modo de acción, 46 actúa como un bloqueador de canal abierto que se une en una posición relativamente profunda dentro del poro acuoso del canal. Se han construido modelos 3D-QSAR empleando la técnica CoMSIA, que correlacionan las propiedades estructurales de la colección de compuestos sintetizados con su actividad. Estos modelos dan soporte a la hipótesis inicial sobre los determinantes estructurales de la actividad antagonista de TRPV1, y constituyen una herramienta para la predicción de la actividad de nuevos compuestos. Usando dichos modelos se predijo una actividad en el rango bajo micromolar para miembros de una familia de analogos basados en un esqueleto central de pirrolidina. La síntesis y evaluación de la actividad antagonista de TRPV1 de alguno de estos análogos confirmó las predicciones, validando dichos modelos 3D-QSAR y estableciendo dichos compuestos como un interesante punto de partida para el desarrollo de una nueva familia de antagonistas.
The ion channel Vanilloid receptor type 1 (TRPV1) is considered an important integrator of various pain stimuli. Among the products that interact with TRPV1, the ones blocking the “pain signal” in an uncompetitive manner have attracted the attention of researchers working in the field. Based on previously obtained results for several peptoid hits that showed activity as uncompetitive TRPV1 antagonists, and that allowed to propose a basic pharmacophoric hypothesis consisting on one cationic and two identical aromatic moieties, this thesis focused on the design and synthesis of new antagonists with a more rigid non-peptoid structure. Biological evaluation of a collection of new blockers and an in depth in vitro and in vivo study of the most active one provided knowledge about their mode of action. In addition, a 3D-quantitative structure-activity relationship study (3D-QSAR) allowed to generate models that explain the observed biological activity and can help to predict the activities of new compounds. The 1,3,5-triazine skeleton was selected as rigid non-peptoid scaffold that can hold the three required pharmacophoric features. A total of 38 2,4,6-trisubstituted-1,3,5-triazines were synthesized using an optimized procedure. An in depth NMR study combined with theoretical calculations allowed to determine that most of these triazines present different conformers in equilibrium in solution, derived from the rotation of the bonds that joint the three side chains to the triazine ring. Ten of those triazines were particularly active blocking TRPV1 with submicromolar IC50 values. Triazine 46 exhibited a remarkably high activity (IC50 = 50 nM) being one of the most potent TRPV1 blockers described. It behaves as a polymodal antagonist against capsaicin and pH activation signals, exhibiting a low toxicity profile both in vitro and in vivo. Concerning its mechanism of action, 46 acts as an open channel blocker that locates relatively deep within the aqueous channel pore. Statistically significant 3D-QSAR models were generated, using the CoMSIA methodology, for the anti-TRPV1 activity of the newly synthesized compounds. Those models reinforced the initial hypothesis on the structural requirements for uncompetitive TRPV1 antagonists and provided a quantitative tool that could help to predict the activity of new compounds. Using these models, an activity in the low micromolar range was estimated for a few members of a new family of pyrrolidine based TRPV1 antagonists. The synthesis and biological evaluation of some of them confirmed the activity prediction, further validating the 3D-QSAR models and establishing these pyrrolidine analogues as an interesting starting point for further development of new anti-TRPV1 compounds.
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Hoffmeister, Carin Gorete Hendges. "PAPEL DO TRPV1 EM UM MODELO ARTICULAR DE GOTA AGUDA EM RATOS." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/3838.
Full textAbstract:
Conselho Nacional de Desenvolvimento Científico e TecnológicoThe gout is an extremely painful type of arthritis. Despite the large number of drugs available for its treatment, they usually cause many adverse effects that limit their use. Then, further investigations are necessary for a better understanding the different mechanisms involved in gout. It was found previously that TRPV1 receptor, an ion channel modulated by various inflammatory mediators mediated edema and the nociceptive responses induced by subcutaneous injection of MSU in rats. In this plantar model, activation of TRPV1 depended largely on the activation of mast cells. Since the environments articular broadly differ as their cellular constituents, questioned the involvement of this receptor in a more reliable model with this clinical arthropathy. The aim of this study was to investigate the role of TRPV1 in a model of acute gout induced by intra-articular administration (i.a.) of crystals of monosodium urate (MSU) tíbio-tarsal articulation rats. It was observed that the antagonism of the TRPV1 receptor (by the selective antagonist SB366791), systemic knockdown (caused by treatment with resiniferatoxin subcutaneous injection a TRPV1 agonist) or axonal silencing (perineural injection a combination of capsaicin and QX-314) sensory fibers TRPV1-positive significantly prevented the pain-related behaviors (spontaneous nociception, heat hyperalgesia, and mechanical allodynia) and inflammation (edema, plasma extravasation, leukocyte infiltration and IL - 1β ) was caused by the administration of MSU. Additionally, we observed a significant increase in immunoreactivity of TRPV1 in articular tissue 4 hours after administration of MSU. Subsequently, we investigated the possibility role of NO, an endogenous activator of TRPV1 in this model. The administration of MSU induced an increase in the production of stable metabolites (NOx) emissions of nitric oxide (NO) exudates in the joint, which was inhibited by a selective inhibitor of nitric oxide synthase (NOS). In addition, the non-selective NOS inhibitor prevented the spontaneous nociception, edema and plasma extravasation, and leukocyte infiltration after MSU injection. Moreover it was found that the administration of a NO donor induced heat hyperalgesia and spontaneous nociception, but not mechanical allodynia and edema. The TRPV1 receptor antagonism prevented only the edema caused by that donor. Thus, these results suggest that TRPV1 plays a role in the development and maintenance of nociceptive and inflammatory responses triggered in the model of acute articular gout, but only edematogenic response appears to be mediated by TRPV1 activation by NO.
A gota é um tipo de artrite extremamente dolorosa. Apesar do grande número de fármacos disponíveis para seu tratamento. Muitos causam efeitos adversos que limitam seu uso. Maiores investigações são necessárias para um melhor entendimento dos diferentes mecanismos envolvidos na gota. Verificou-se previamente que o receptor TRPV1, um canal iônico modulado por vários mediadores inflamatórios, mediou as respostas nociceptiva e edematogênica induzidas pela injeção subcutânea de MSU em ratos. Neste modelo plantar, a ativação do TRPV1 dependeu amplamente da ativação de mastócitos. Sendo o ambiente articular amplamente diferenciado quanto a sua constituição celular, questionou-se o envolvimento deste receptor em um modelo mais fidedigno com a clínica dessa artropatia. O objetivo deste estudo foi investigar o papel do TRPV1 em um modelo de gota aguda, induzida pela administração intra-articular (i.a.) de cristais de urato monossódico (MSU) na articulação tíbio-tarsal de ratos. Observou-se que o antagonismo do receptor TRPV1 (pelo antagonista seletivo do receptor TRPV1 SB366791), a desfuncionalização sistêmica (causada pelo tratamento subcutâneo com resiniferatoxina) ou o silenciamento axonal (com a combinação periciática de capsaicina e QX 314) das fibras sensoriais TRPV1-positivas preveniram significativamente os comportamentos relacionados à dor (nocicepção expontânea, hiperalgesia ao calor e alodínea mecânica) e à inflamação (edema, extravasamento plasmático, infiltração de leucócitos e produção de IL-1β) causadas pela administração i.a. de MSU. Adicionalmente, observou-se um aumento expressivo da imunoreatividade do TRPV1 no tecido articular 4 horas após a administração do MSU. Posteriormente investigou-se a possibilidade do NO ser um ativador endógeno do TRPV1 neste modelo. Demonstrou-se que a administração i.a. de MSU induziu um aumento na produção de metabólitos estáveis (NOx) do óxido nítrico (NO) nos exsudatos articulares, o qual foi inibido pela administração i.a. de um inibidor não seletivo da óxido nítrico sintase (NOS). Além disso, o inibidor não seletivo da NOS preveniu a nocicepção espontânea, o edema e também o extravasamento plasmático, a infiltração de leucócitos. Por outro lado constatou-se que a administração i.a. de um doador de NO induziu nocicepção espontânea e hiperalgesia ao calor, mas não alodínea mecânica ou edema. O antagonismo do receptor TRPV1 preveniu somente o edema causado por esse doador. Assim, estes resultados sugerem que o TRPV1 exerce um papel relevante no desenvolvimento e manutenção das respostas nociceptiva e inflamatória desencadeadas no modelo articular de crise aguda de gota, porém, apenas a resposta edematogênica parece ser mediada pela ativação TRPV1 através do NO.