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Kamp, Marcel A., Maxine Dibué, Toni Schneider, Hans-Jakob Steiger e Daniel Hänggi. "Calcium and Potassium Channels in Experimental Subarachnoid Hemorrhage and Transient Global Ischemia". Stroke Research and Treatment 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/382146.
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Healthy cerebrovascular myocytes express members of several different ion channel families which regulate resting membrane potential, vascular diameter, and vascular tone and are involved in cerebral autoregulation. In animal models, in response to subarachnoid blood, a dynamic transition of ion channel expression and function is initiated, with acute and long-term effects differing from each other. Initial hypoperfusion after exposure of cerebral vessels to oxyhemoglobin correlates with a suppression of voltage-gated potassium channel activity, whereas delayed cerebral vasospasm involves changes in other potassium channel and voltage-gated calcium channels expression and function. Furthermore, expression patterns and function of ion channels appear to differ between main and small peripheral vessels, which may be key in understanding mechanisms behind subarachnoid hemorrhage-induced vasospasm. Here, changes in calcium and potassium channel expression and function in animal models of subarachnoid hemorrhage and transient global ischemia are systematically reviewed and their clinical significance discussed.
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Kazama, Itsuro. "Roles of Lymphocyte Kv1.3-Channels in the Pathogenesis of Renal Diseases and Novel Therapeutic Implications of Targeting the Channels". Mediators of Inflammation 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/436572.
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Delayed rectifier K+-channels (Kv1.3) are predominantly expressed in T lymphocytes. Based on patch-clamp studies, the channels play crucial roles in facilitating the calcium influx necessary to trigger lymphocyte activation and proliferation. Using selective channel inhibitors in experimental animal models,in vivostudies then revealed the clinically relevant relationship between the channel expression and the pathogenesis of autoimmune diseases. In renal diseases, in which “chronic inflammation” or “the overstimulation of cellular immunity” is responsible for the pathogenesis, the overexpression of Kv1.3-channels in lymphocytes promotes their cellular proliferation and thus contributes to the progression of tubulointerstitial fibrosis. We recently demonstrated that benidipine, a potent dihydropyridine calcium channel blocker, which also strongly and persistently inhibits the lymphocyte Kv1.3-channel currents, suppressed the proliferation of kidney lymphocytes and actually ameliorated the progression of renal fibrosis. Based on the recentin vitroevidence that revealed the pharmacological properties of the channels, the most recent studies have revealed novel therapeutic implications of targeting the lymphocyte Kv1.3-channels for the treatment of renal diseases.
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Uchitel, Osvaldo D., Carlota González Inchauspe e Mariano N. Di Guilmi. "Calcium channels and synaptic transmission in familial hemiplegic migraine type 1 animal models". Biophysical Reviews 6, n.º 1 (3 de dezembro de 2013): 15–26. http://dx.doi.org/10.1007/s12551-013-0126-y.
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Bakowski, Daniel, Fraser Murray e Anant B. Parekh. "Store-Operated Ca2+ Channels: Mechanism, Function, Pharmacology, and Therapeutic Targets". Annual Review of Pharmacology and Toxicology 61, n.º 1 (6 de janeiro de 2021): 629–54. http://dx.doi.org/10.1146/annurev-pharmtox-031620-105135.
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Calcium (Ca2+) release–activated Ca2+ (CRAC) channels are a major route for Ca2+ entry in eukaryotic cells. These channels are store operated, opening when the endoplasmic reticulum (ER) is depleted of Ca2+, and are composed of the ER Ca2+ sensor protein STIM and the pore-forming plasma membrane subunit Orai. Recent years have heralded major strides in our understanding of the structure, gating, and function of the channels. Loss-of-function and gain-of-function mutants combined with RNAi knockdown strategies have revealed important roles for the channel in numerous human diseases, making the channel a clinically relevant target. Drugs targeting the channels generally lack specificity or exhibit poor efficacy in animal models. However, the landscape is changing, and CRAC channel blockers are now entering clinical trials. Here, we describe the key molecular and biological features of CRAC channels, consider various diseases associated with aberrant channel activity, and discuss targeting of the channels from a therapeutic perspective.
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Tano, Jean-Yves, e Maik Gollasch. "Hypoxia and ischemia-reperfusion: a BiK contribution?" American Journal of Physiology-Heart and Circulatory Physiology 307, n.º 6 (15 de setembro de 2014): H811—H817. http://dx.doi.org/10.1152/ajpheart.00319.2014.
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Over the last decades, cardiovascular disease has become the primary cause of death in the Western world, and this trend is expanding throughout the world. In particular, atherosclerosis and the subsequent vessel obliterations are the primary cause of ischemic disease (stroke and coronary heart disease). Excess calcium influx into the cells is one of the major pathophysiological mechanisms important for ischemic injury in the brain and heart in humans. The large-conductance calcium-activated K+ channels (BK) are thus interesting candidates to protect against excess calcium influx and the events leading to ischemic injury. Indeed, the mitochondrial BK channels (mitoBK) have recently been shown to play a protective function against ischemia-reperfusion injury both in vitro and in animal models, although the exact mechanism of this protection is still under scrutiny. In addition, in both the plasma membrane and mitochondrial BK channel, the α-subunit itself is sensitive to hypoxia. This sensitivity is tissue specific and conferred by a highly conserved motif within an alternatively spliced cysteine-rich insert (STREX) in the intracellular C terminus of the channel. This review describes recent developments of the increasing relevance of BK channels in hypoxia and ischemia-reperfusion injury.
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Falcón, Débora, Isabel Galeano-Otero, Marta Martín-Bórnez, María Fernández-Velasco, Isabel Gallardo-Castillo, Juan A. Rosado, Antonio Ordóñez e Tarik Smani. "TRPC Channels: Dysregulation and Ca2+ Mishandling in Ischemic Heart Disease". Cells 9, n.º 1 (10 de janeiro de 2020): 173. http://dx.doi.org/10.3390/cells9010173.
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Transient receptor potential canonical (TRPC) channels are ubiquitously expressed in excitable and non-excitable cardiac cells where they sense and respond to a wide variety of physical and chemical stimuli. As other TRP channels, TRPC channels may form homo or heterotetrameric ion channels, and they can associate with other membrane receptors and ion channels to regulate intracellular calcium concentration. Dysfunctions of TRPC channels are involved in many types of cardiovascular diseases. Significant increase in the expression of different TRPC isoforms was observed in different animal models of heart infarcts and in vitro experimental models of ischemia and reperfusion. TRPC channel-mediated increase of the intracellular Ca2+ concentration seems to be required for the activation of the signaling pathway that plays minor roles in the healthy heart, but they are more relevant for cardiac responses to ischemia, such as the activation of different factors of transcription and cardiac hypertrophy, fibrosis, and angiogenesis. In this review, we highlight the current knowledge regarding TRPC implication in different cellular processes related to ischemia and reperfusion and to heart infarction.
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Prestori, Francesca, Francesco Moccia e Egidio D’Angelo. "Disrupted Calcium Signaling in Animal Models of Human Spinocerebellar Ataxia (SCA)". International Journal of Molecular Sciences 21, n.º 1 (27 de dezembro de 2019): 216. http://dx.doi.org/10.3390/ijms21010216.
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Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of more than 40 autosomal-dominant genetic and neurodegenerative diseases characterized by loss of balance and motor coordination due to dysfunction of the cerebellum and its efferent connections. Despite a well-described clinical and pathological phenotype, the molecular and cellular events that underlie neurodegeneration are still poorly undaerstood. Emerging research suggests that mutations in SCA genes cause disruptions in multiple cellular pathways but the characteristic SCA pathogenesis does not begin until calcium signaling pathways are disrupted in cerebellar Purkinje cells. Ca2+ signaling in Purkinje cells is important for normal cellular function as these neurons express a variety of Ca2+ channels, Ca2+-dependent kinases and phosphatases, and Ca2+-binding proteins to tightly maintain Ca2+ homeostasis and regulate physiological Ca2+-dependent processes. Abnormal Ca2+ levels can activate toxic cascades leading to characteristic death of Purkinje cells, cerebellar atrophy, and ataxia that occur in many SCAs. The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells via inhibitory signals; thus, Purkinje cell dysfunction or degeneration would partially or completely impair the cerebellar output in SCAs. In the absence of the inhibitory signal emanating from Purkinje cells, DCN will become more excitable, thereby affecting the motor areas receiving DCN input and resulting in uncoordinated movements. An outstanding advantage in studying the pathogenesis of SCAs is represented by the availability of a large number of animal models which mimic the phenotype observed in humans. By mainly focusing on mouse models displaying mutations or deletions in genes which encode for Ca2+ signaling-related proteins, in this review we will discuss the several pathogenic mechanisms related to deranged Ca2+ homeostasis that leads to significant Purkinje cell degeneration and dysfunction.
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Crotti, Lia, Katja E. Odening e Michael C. Sanguinetti. "Heritable arrhythmias associated with abnormal function of cardiac potassium channels". Cardiovascular Research 116, n.º 9 (19 de maio de 2020): 1542–56. http://dx.doi.org/10.1093/cvr/cvaa068.
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Abstract Cardiomyocytes express a surprisingly large number of potassium channel types. The primary physiological functions of the currents conducted by these channels are to maintain the resting membrane potential and mediate action potential repolarization under basal conditions and in response to changes in the concentrations of intracellular sodium, calcium, and ATP/ADP. Here, we review the diversity and functional roles of cardiac potassium channels under normal conditions and how heritable mutations in the genes encoding these channels can lead to distinct arrhythmias. We briefly review atrial fibrillation and J-wave syndromes. For long and short QT syndromes, we describe their genetic basis, clinical manifestation, risk stratification, traditional and novel therapeutic approaches, as well as insights into disease mechanisms provided by animal and cellular models.
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Schoepf, Clemens L., Maximilian Zeidler, Lisa Spiecker, Georg Kern, Judith Lechner, Kai K. Kummer e Michaela Kress. "Selected Ionotropic Receptors and Voltage-Gated Ion Channels: More Functional Competence for Human Induced Pluripotent Stem Cell (iPSC)-Derived Nociceptors". Brain Sciences 10, n.º 6 (3 de junho de 2020): 344. http://dx.doi.org/10.3390/brainsci10060344.
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Preclinical research using different rodent model systems has largely contributed to the scientific progress in the pain field, however, it suffers from interspecies differences, limited access to human models, and ethical concerns. Human induced pluripotent stem cells (iPSCs) offer major advantages over animal models, i.e., they retain the genome of the donor (patient), and thus allow donor-specific and cell-type specific research. Consequently, human iPSC-derived nociceptors (iDNs) offer intriguingly new possibilities for patient-specific, animal-free research. In the present study, we characterized iDNs based on the expression of well described nociceptive markers and ion channels, and we conducted a side-by-side comparison of iDNs with mouse sensory neurons. Specifically, immunofluorescence (IF) analyses with selected markers including early somatosensory transcription factors (BRN3A/ISL1/RUNX1), the low-affinity nerve growth factor receptor (p75), hyperpolarization-activated cyclic nucleotide-gated channels (HCN), as well as high voltage-gated calcium channels (VGCC) of the CaV2 type, calcium permeable TRPV1 channels, and ionotropic GABAA receptors, were used to address the characteristics of the iDN phenotype. We further combined IF analyses with microfluorimetric Ca2+ measurements to address the functionality of these ion channels in iDNs. Thus, we provide a detailed morphological and functional characterization of iDNs, thereby, underpinning their enormous potential as an animal-free alternative for human specific research in the pain field for unveiling pathophysiological mechanisms and for unbiased, disease-specific personalized drug development.
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Othman e Hamurtekin. "A New Pain Killer from the Nature: N-Type Calcium Channels Blockers". Proceedings 40, n.º 1 (8 de fevereiro de 2020): 47. http://dx.doi.org/10.3390/proceedings2019040047.
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N-type calcium channels (Neuronal-type Calcium channel, Cav2.2) is a member of high voltage activated calcium channels. There are two native small peptides for N-type calcium channels (NTCC) directly which are derived from cone snail, ω-conotoxin-GVIA isolated from Conus geographus and ω-conotoxin-MVIIA (SNX-111, Ziconotide, PrialtTM), from Conus magus which both directly block the α1-ion conducting pore. NTCCs, have been shown to play a key role in nociceptive transmission due to their strategic location, presynaptically in afferent C & Aᵹ fiber terminals and postsynaptically in descending neuron. NTCCs, which are highly expressed at the pre-synaptic terminals of nociceptive neurons in dorsal horn of the spinal cord regulate release of the key pro-nociceptive neurotransmitters such as glutamate, substance P, neurokinin A, and CGRP. There have been many preclinical studies demonstrating the effect of different NTCC blockers in various acute, inflammatory and neuropathic animal pain models. In 2004 ziconotide has been approved in US and Europe to be used in clinical practice. Furthermore, many clinical trials have been performed in more than 1000 patients studying the efficacy and safety of ziconotide. IT administrated of ziconotide showed significant decrease in pain scores in patients with malignant and nonmalignant pain which are practically in neuropathic pain characteristic and resistant to IT opioids.
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Honoré, Per Hartvig, Anna Basnet, Pernille Kristensen, Lene Munkholm Andersen, Signe Neustrup, Pia Møllgaard, Laila Eljaja e Ole J. Bjerrum. "Predictive validity of pharmacologic interventions in animal models of neuropathic pain". Scandinavian Journal of Pain 2, n.º 4 (1 de outubro de 2011): 178–84. http://dx.doi.org/10.1016/j.sjpain.2011.06.002.
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AbstractIntroductionThe pathophysiologic and neurochemical characteristics of neuropathic pain must be considered in the search for new treatment targets. Breakthroughs in the understanding of the structural and biochemical changes in neuropathy have opened up possibilities to explore new treatment paradigms. However, long term sequels from the damage are still difficult to treat.Aim of the studyTo examine the validity of pharmacological treatments in humans and animals for neuropathic pain.MethodAn overview from the literature and own experiences of pharmacological treatments employed to interfere in pain behavior in different animal models was performed.ResultsThe treatment principles tested in animal models of neuropathic pain may have predictive validity for treatment of human neuropathies. Opioids, neurotransmitter blockers, drugs interfering with the prostaglandin syntheses as well as voltage gated sodium channel blockers and calcium channel blockers are treatment principles having efficacy and similar potency in humans and in animals. Alternative targets have been identified and have shown promising results in the validated animal models. Modulators of the glutamate system with an increased expression of glutamate re-uptake transporters, inhibition of pain promoters as nitric oxide and prostaglandins need further exploration. Modulation of cytokines and neurotrophins in neuropathic pain implies new targets for study. Further, a combination of different analgesic treatments may as well improve management of neuropathic pain, changing the benefit/risk ratio.ImplicationsNot surprisingly most pharmacologic principles that are tested in animal models of neuropathic pain are also found to be active in humans. Whereas many candidate drugs that were promising in animal models of neuropathic pain turned out not to be effective or too toxic in humans, animal models for neuropathic pain are still the best tools available to learn more about mechanisms of neuropathic pain. Better understanding of pathogenesis is the most hopeful approach to improve treatment of neuropathic pain.
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DE, VRY J., K. R. JENTZSCH e G. ECKEL. "EFFECTS OF THE L-TYPE CALCIUM CHANNEL ANTAGONIST NIMODIPINE IN ANIMAL MODELS OF DEPRESSION". Behavioural Pharmacology 7, Supplement 1 (maio de 1996): 28. http://dx.doi.org/10.1097/00008877-199605001-00062.
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Mason, W. T., S. R. Rawlings, P. Cobbett, S. K. Sikdar, R. Zorec, S. N. Akerman, C. D. Benham, M. J. Berridge, T. Cheek e R. B. Moreton. "Control of secretion in anterior pituitary cells--linking ion channels, messengers and exocytosis". Journal of Experimental Biology 139, n.º 1 (1 de setembro de 1988): 287–316. http://dx.doi.org/10.1242/jeb.139.1.287.
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Normal anterior pituitary cells, in their diversity and heterogeneity, provide a rich source of models for secretory function. However, until recently they have largely been neglected in favour of neoplastic, clonal tumour cell lines of pituitary origin, which have enabled a number of studies on supposedly homogeneous cell types. Because many of these lines appear to lack key peptide and neurotransmitter receptors, as well as being degranulated with accompanying abnormal levels of secretion, we have developed a range of normal primary anterior pituitary cell cultures using dispersion and enrichment techniques. By studying lactotrophs, somatotrophs and gonadotrophs we have revealed a number of possible transduction mechanisms by which receptors for hypothalamic peptides and neurotransmitters may control secretion. In particular, the transduction events controlling secretion from pituitary cells may differ fundamentally from those found in other cell types. Patch-clamp recordings in these various pituitary cell preparations have revealed substantial populations of voltage-dependent Na+, Ca2+ and K+ channels which may support action potentials in these cells. Although activation of these channels may gate Ca2+ entry to the cells under some conditions, our evidence taken with that of other laboratories suggests that peptide-receptor interactions leading to hormone secretion occur independently of significant membrane depolarization. Rather, secretion of hormone and rises in intracellular calcium measured with new probes for intracellular calcium activity, can occur in response to hypothalamic peptide activation in the absence of substantial changes in membrane potential. These changes in intracellular calcium activity almost certainly depend on both intracellular and extracellular calcium sources. In addition, strong evidence of a role for multiple intracellular receptors and modulators in the secretory event suggests we should consider the plasma membrane channels important for regulation of hormone secretion to be predominantly agonist-activated, rather than of the more conventional voltage-dependent type. Likewise, evidence from new methods for recording single ion channels suggests the existence of intracellular sites for channel modulation, implying they too may play an important role in secretory regulation. We shall consider new data and new technology which we hope will provide key answers to the many intriguing questions surrounding the control of pituitary hormone secretion. We shall highlight our work with recordings of single ion channels activated by peptides, and recent experiments using imaging of intracellular ionized free calcium.(ABSTRACT TRUNCATED AT 250 WORDS)
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Ripsch, Matthew, Carrie Ballard, May Khanna, Joyce Hurley, Fletcher White e Rajesh Khanna. "A peptide uncoupling CRMP-2 from the presynaptic Ca2+ channel complex demonstrates efficacy in animal models of migraine and AIDS therapy-induced neuropathy". Translational Neuroscience 3, n.º 1 (1 de janeiro de 2012): 1–8. http://dx.doi.org/10.2478/s13380-012-0002-4.
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AbstractBiological, genetic, and clinical data provide compelling proof for N-type voltage-gated calcium channels (CaV2.2) as therapeutic targets for chronic pain. While decreasing channel function is ultimately anti-nociceptive, directly targeting the channel can lead to multiple adverse effects. Targeting regulators of channel activity may facilitate improved analgesic properties associated with channel block and afford a broader therapeutic window. Towards this end, we recently identified a short peptide, designated CBD3, derived from collapsin response mediator protein 2 (CRMP-2) that suppressed inflammatory and neuropathic hypersensitivity by inhibiting CRMP-2 binding to CaV2.2 [Brittain et al., Nature Medicine 17:822–829 (2011)]. Rodents administered CBD3 intraperitoneally, fused to the HIV TAT protein cell penetrating domain, exhibited antinociception lasting ∼4 hours highlighting potential instability, limited oral bioavailability, and/or rapid elimination of peptide. This report focuses on improving upon the parental CBD3 peptide. Using SPOTScan analysis of synthetic versions of the parental CBD3 peptide, we identified peptides harboring single amino acid mutations that bound with greater affinity to CaV2.2. One such peptide, harboring a phenylalanine instead of glycine (G14F), was tested in rodent models of migraine and neuropathic pain. In vivo laser Doppler blood flowmetry measure of capsaicin-induced meningeal vascular responses related to headache pain was almost completely suppressed by dural application of the G14F peptide. The G14F mutant peptide, administered intraperitoneally, also exhibited greater antinociception in Stavudine (2′-3′-didehydro-2′-3′-dideoxythymidine (d4T)/Zerit®) model of AIDS therapy-induced peripheral neuropathy compared to the parent CBD3 peptide. These results demonstrate the patent translational value of small biologic drugs targeting CaV2.2 for management of clinical pain.
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Saeki, Kensuke, Shun-ichi Yasuda, Masami Kato, Mayumi Kano, Yuki Domon, Naohisa Arakawa e Yutaka Kitano. "Analgesic effects of mirogabalin, a novel ligand for α2δ subunit of voltage-gated calcium channels, in experimental animal models of fibromyalgia". Naunyn-Schmiedeberg's Archives of Pharmacology 392, n.º 6 (15 de fevereiro de 2019): 723–28. http://dx.doi.org/10.1007/s00210-019-01628-z.
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Bailey, Cole S., Hans J. Moldenhauer, Su Mi Park, Sotirios Keros e Andrea L. Meredith. "KCNMA1-linked channelopathy". Journal of General Physiology 151, n.º 10 (19 de agosto de 2019): 1173–89. http://dx.doi.org/10.1085/jgp.201912457.
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KCNMA1 encodes the pore-forming α subunit of the “Big K+” (BK) large conductance calcium and voltage-activated K+ channel. BK channels are widely distributed across tissues, including both excitable and nonexcitable cells. Expression levels are highest in brain and muscle, where BK channels are critical regulators of neuronal excitability and muscle contractility. A global deletion in mouse (KCNMA1−/−) is viable but exhibits pathophysiology in many organ systems. Yet despite the important roles in animal models, the consequences of dysfunctional BK channels in humans are not well characterized. Here, we summarize 16 rare KCNMA1 mutations identified in 37 patients dating back to 2005, with an array of clinically defined pathological phenotypes collectively referred to as “KCNMA1-linked channelopathy.” These mutations encompass gain-of-function (GOF) and loss-of-function (LOF) alterations in BK channel activity, as well as several variants of unknown significance (VUS). Human KCNMA1 mutations are primarily associated with neurological conditions, including seizures, movement disorders, developmental delay, and intellectual disability. Due to the recent identification of additional patients, the spectrum of symptoms associated with KCNMA1 mutations has expanded but remains primarily defined by brain and muscle dysfunction. Emerging evidence suggests the functional BK channel alterations produced by different KCNMA1 alleles may associate with semi-distinct patient symptoms, such as paroxysmal nonkinesigenic dyskinesia (PNKD) with GOF and ataxia with LOF. However, due to the de novo origins for the majority of KCNMA1 mutations identified to date and the phenotypic variability exhibited by patients, additional evidence is required to establish causality in most cases. The symptomatic picture developing from patients with KCNMA1-linked channelopathy highlights the importance of better understanding the roles BK channels play in regulating cell excitability. Establishing causality between KCNMA1-linked BK channel dysfunction and specific patient symptoms may reveal new treatment approaches with the potential to increase therapeutic efficacy over current standard regimens.
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Yam, Mun Fei, Chu Shan Tan, Mariam Ahmad e Shibao Ruan. "Vasorelaxant Action of the Chloroform Fraction of Orthosiphon stamineus via NO/cGMP Pathway, Potassium and Calcium Channels". American Journal of Chinese Medicine 44, n.º 07 (janeiro de 2016): 1413–39. http://dx.doi.org/10.1142/s0192415x16500798.
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Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that is used to treat hypertension and kidney stones. In humans, this plant has been tested as an addition regiment for antihypertensive treatment. Among the treatments for hypertension, O. stamineus had been to have diuretic and vasorelaxant effects in animal models. There is still very little information regarding the vasorelaxant effect of O. stamineus. Therefore, the present study was designed to investigate the vasorelaxant activity and mechanism of action of the fractions of O. stamineus. The vasorelaxant activity and the underlying mechanisms of the chloroform fraction of the 50% methanolic extract of O. stamineus (CF) was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. CF caused relaxation of the aortic ring pre-contracted with phenylephrine in the presence and absence of endothelium, and pre-contracted with potassium chloride in endothelium-intact aortic ring. In the presence of endothelium, both indomethacin (a nonselective cyclooxygenase inhibitor) and [Formula: see text]-[1,2,4]Oxadiazolo[4,3-[Formula: see text]]quinoxalin-1-one (ODQ, selective soluble guanylate cyclase inhibitor) had a small effect on the vasorelaxation response. On the other hand, in the presence of Nω-nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor), methylene blue (cyclic guanosine monophosphate lowering agent), tetraethylammonium ([Formula: see text], nonselective calcium activator [Formula: see text] channel blocker), 4-aminopyridine (4-AP, voltage-dependent [Formula: see text] channel blocker), barium chloride ([Formula: see text], inwardly rectifying [Formula: see text] channel blocker), glibenclamide (nonspecific ATP-sensitive [Formula: see text] channel blocker), atropine (muscarinic receptor blocker) and propranolol (β-adrenergic receptor blocker), the vasorelaxant effect significantly reduced the relaxation stimulated by CF. CF was also found to be active in reducing [Formula: see text] release from the sarcoplasmic reticulum and blocking calcium channels.
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Cohan, Stanley L., David J. Redmond, Mei Chen, Dahlia Wilson e Philip Cyr. "Flunarizine Blocks Elevation of Free Cytosolic Calcium in Synaptosomes following Sustained Depolarization". Journal of Cerebral Blood Flow & Metabolism 13, n.º 6 (novembro de 1993): 947–54. http://dx.doi.org/10.1038/jcbfm.1993.118.
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Gerbil cerebral cortical synaptosomes loaded with the fluorescent calcium probe FURA-2 were used to study depolarization-induced presynaptic cytosolic free calcium concentration, as an in vitro model of cerebral ischemia. The depolarization-induced increase in intrasynaptosomal cytosolic free calcium concentration is not sodium-dependent or sodium channel-dependent and may be due to an influx of extrasynaptosomal calcium resulting from a cadmium- and omega-conotoxin-sensitive, nickel-, nifedipine-, and nimodipine-insensitive voltage-regulated channel. The depolarization-induced increase in intrasynaptosomal free cytosolic calcium concentration is also inhibited by flunarizine, a calcium antagonist that has protective effects in animal models of cerebral anoxia and ischemia. Our results suggest that presynaptic calcium uptake following depolarization may be mediated in part by an N-type channel. Flunarizine may block presynaptic calcium accumulation, in part, by blocking this N-type channel; this blockade may be just one of several mechanisms by which flunarizine exerts protective effects following cerebral ischemia.
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Zoerle, Tommaso, Don C. Ilodigwe, Hoyee Wan, Katarina Lakovic, Mohammed Sabri, Jinglu Ai e R. Loch Macdonald. "Pharmacologic Reduction of Angiographic Vasospasm in Experimental Subarachnoid Hemorrhage: Systematic Review and Meta-Analysis". Journal of Cerebral Blood Flow & Metabolism 32, n.º 9 (25 de abril de 2012): 1645–58. http://dx.doi.org/10.1038/jcbfm.2012.57.
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Animal models have been developed to simulate angiographic vasospasm secondary to subarachnoid hemorrhage (SAH) and to test pharmacologic treatments. Our aim was to evaluate the effect of pharmacologic treatments that have been tested in humans and in preclinical studies to determine if animal models inform results reported in humans. A systematic review and meta-analysis of SAH studies was performed. We investigated predictors of translation from animals to humans with multivariate logistic regression. Pharmacologic reduction of vasospasm was effective in mice, rats, rabbits, dogs, nonhuman primates (standard mean difference of −1.74; 95% confidence interval −2.04 to −1.44) and humans. Animal studies were generally of poor methodologic quality and there was evidence of publication bias. Subgroup analysis by drug and species showed that statins, tissue plasminogen activator, erythropoietin, endothelin receptor antagonists, calcium channel antagonists, fasudil, and tirilazad were effective whereas magnesium was not. Only evaluation of vasospasm >3 days after SAH was independently associated with successful translation. We conclude that reduction of vasospasm is effective in animals and humans and that evaluation of vasospasm >3 days after SAH may be preferable for preclinical models.
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Turley, Sarah L., Kerry E. Francis, Denise K. Lowe e William D. Cahoon. "Emerging role of ivabradine for rate control in atrial fibrillation". Therapeutic Advances in Cardiovascular Disease 10, n.º 6 (22 de setembro de 2016): 348–52. http://dx.doi.org/10.1177/1753944716669658.
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Control of ventricular rate is recommended for patients with paroxysmal, persistent, or permanent atrial fibrillation (AF). Existing rate-control options, including beta-blockers, nondihydropyridine calcium channel blockers, and digoxin, are limited by adverse hemodynamic effects and their ability to attain target heart rate (HR). Ivabradine, a novel HR-controlling agent, decreases HR through deceleration of conduction through If (‘funny’) channels, and is approved for HR reduction in heart failure patients with ejection fraction less than 35% and elevated HR, despite optimal pharmacological treatment. Because If channels were thought to be expressed solely in sinoatrial (SA) nodal tissue, ivabradine was not investigated in heart failure patients with concomitant AF. Subsequent identification of hyperpolarization-activated cyclic nucleotide-gated cation channel 4 (HCN4), the primary gene responsible for If current expression throughout the myocardium, stimulated interest in the potential role of ivabradine for ventricular rate control in AF. Preclinical studies of ivabradine in animal models with induced AF demonstrated a reduction in HR, with no significant worsening of QT interval or mean arterial pressure. Preliminary human data suggest that ivabradine provides HR reduction without associated hemodynamic complications in patients with AF. Questions remain regarding efficacy, safety, optimal dosing, and length of therapy in these patients. Prospective, randomized studies are needed to determine if ivabradine has a role as a rate-control treatment in patients with AF.
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Riva, M. A. "Epigenetic Signatures of Early Life Adversities in Animal Models: A Role for Psychopathology Vulnerability". European Psychiatry 41, S1 (abril de 2017): S29. http://dx.doi.org/10.1016/j.eurpsy.2017.01.145.
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Stressful experiences early in life (ELS) represent one of the most relevant factors for the vulnerability to psychopathologies. Epigenetic changes, such as DNA methylation, have emerged as a major mechanism through which ELS can alter adult behaviour leading to persistent changes of gene regulation.We performed DNA methylation analyses in the hippocampus and prefrontal cortex of adult rats exposed to stress during gestation (PNS), a model that is associated with persistent behavioral alterations relevant for psychiatric disorders.Using an epigenome-wide analysis, an overlap of 893 differentially methylated genes was observed between hippocampus and prefrontal cortex of adult male and female rats exposed to PNS. The list includes several genes previously associated with schizophrenia and other psychiatric conditions, such as calcium and potassium voltage operated channels as well as GABA and glutamate receptor subunits. By restricting the overlap to genes that were modulated in the same direction, we identified miR-30a as being less methylated in PNS rats. Interestingly one of the targets for this miRNA is the neurotrophin BDNF, whose expression was indeed reduced as a consequence of the prenatal manipulation. Interestingly chronic treatment of PNS rats with the multi-receptor modulator lurasidone during adolescence was able to prevent the changes in miR30a and BDNF expression.These results highlight the importance for the identification of methylation signatures through which stress exposure early in life could engrave on the outcome of the adult phenotype, and may allow the identification of novel genes and pathways that are affected as a consequence of ELS.Disclosure of interestM.A.R. has received compensation as speaker/consultant from Lundbeck, Otzuka, Sumitomo Dainippon Pharma and Sunovion. He has received research grants from Lundbeck, Sumitomo Dainippon Pharma and Sunovion.
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Hori, Takayuki, Motoshi Ouchi, Naoyuki Otani, Masakatsu Nohara, Asuka Morita, Yusuke Otsuka, Promsuk Jutabha et al. "The uricosuric effects of dihydropyridine calcium channel blockers in vivo using urate under-excretion animal models". Journal of Pharmacological Sciences 136, n.º 4 (abril de 2018): 196–202. http://dx.doi.org/10.1016/j.jphs.2017.11.011.
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Berridge, M. J. "Elementary and global aspects of calcium signalling." Journal of Experimental Biology 200, n.º 2 (1 de janeiro de 1997): 315–19. http://dx.doi.org/10.1242/jeb.200.2.315.
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Calcium is a ubiquitous second messenger used to regulate a wide range of cellular processes. This role in signalling has to be conducted against the rigid homeostatic mechanisms that ensure that the resting level of Ca2+ is kept low (i.e. between 20 and 100 nmol l-1) in order to avoid the cytotoxic effects of a prolonged elevation of [Ca2+]. Cells have evolved a sophisticated signalling system based on the generation of brief pulses of Ca2+ which enables this ion to be used as a messenger, thus avoiding its toxic effects. Such Ca2+ spikes usually result from the coordinated release of Ca2+ from internal stores using either inositol 1,4,5-trisphosphate or ryanodine receptors. Using Ca2+ imaging techniques, the opening of individual channels has now been visualized and models have been proposed to explain how these elementary events are coordinated to generate the global Ca2+ signals that regulate cellular activity.
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Daly, Norelle L., Brid Callaghan, Richard J. Clark, Simon T. Nevin, David J. Adams e David J. Craik. "Structure and Activity of α-Conotoxin PeIA at Nicotinic Acetylcholine Receptor Subtypes and GABAB Receptor-coupled N-type Calcium Channels". Journal of Biological Chemistry 286, n.º 12 (20 de janeiro de 2011): 10233–37. http://dx.doi.org/10.1074/jbc.m110.196170.
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α-Conotoxins are peptides from cone snails that target the nicotinic acetylcholine receptor (nAChR). RgIA and Vc1.1 have analgesic activity in animal pain models. Both peptides target the α9α10 nAChR and inhibit N-type calcium channels via GABAB receptor activation, but the mechanism of action of analgesic activity is unknown. PeIA has previously been shown to inhibit the α9α10 and α3β2 nAChRs. In this study, we have determined the structure of PeIA and shown that it is also a potent inhibitor of N-type calcium channels via GABAB receptor activation. The characteristic α-conotoxin fold is present in PeIA, but it has a different distribution of surface-exposed hydrophobic and charged residues compared with Vc1.1. Thus, the surface residue distribution, rather than the overall fold, appears to be responsible for the 50-fold increase in selectivity at the α3β2 nAChR by PeIA relative to Vc1.1. In contrast to their difference in potency at the nAChR, the equipotent activity of PeIA and Vc1.1 at the GABAB receptor suggests that the GABAB receptor is more tolerant to changes in surface residues than is the nAChR. The conserved Asp-Pro-Arg motif of Vc1.1 and RgIA, which is crucial for potency at the α9α10 nAChR, is not required for activity at GABAB receptor/N-type calcium channels because PeIA has a His-Pro-Ala motif in the equivalent position. This study shows that different structure-activity relationships are associated with the targeting of the GABAB receptor versus nAChRs. Furthermore, there is probably a much more diverse range of conotoxins that target the GABAB receptor than currently realized.
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Shepherd, Greene, e Wendy Klein-Schwartz. "High-Dose Insulin Therapy for Calcium-Channel Blocker Overdose". Annals of Pharmacotherapy 39, n.º 5 (maio de 2005): 923–30. http://dx.doi.org/10.1345/aph.1e436.
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OBJECTIVE: To evaluate the evidence for using high-dose insulin therapy with supplemental dextrose and potassium in calcium-channel blocker (CCB) overdose. DATA SOURCES: Evidence of efficacy for high-dose insulin therapy with supplemental dextrose and potassium was sought by performing a search of MEDLINE and Toxline between 1966 and July 2004 using combinations of the terms calcium-channel blocker, overdose, poisoning, antidote, and insulin. Abstracts from the North American Congress of Clinical Toxicology for the years 1996–2003 were also reviewed. STUDY SELECTION AND DATA EXTRACTION: Identified articles, including animal studies, case reports, and case series, were evaluated for this review. No clinical trials were available. DATA SYNTHESIS: Animal models of CCB overdose demonstrate that high-dose insulin with supplemental dextrose and potassium was a more effective therapy than calcium, glucagon, or catecholamines. High-dose insulin appears to enhance cardiac carbohydrate metabolism and has direct inotropic effects. Published clinical experience is limited to 13 case reports where insulin was used after other therapies were failing; 12 of these patients survived. High-dose insulin therapy was beneficial for CCB-induced hypotension, hyperglycemia, and metabolic acidosis. Bradycardia and heart block resolved in some patients, but persisted in others. CONCLUSIONS: Based on animal data and limited human experience, as well as the inadequacies of available alternatives for patients with significant poisoning, high-dose insulin therapy warrants further study and judicious use in patients with life-threatening CCB poisoning.
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Yan, Simin, Thomas C. Resta e Nikki L. Jernigan. "Vasoconstrictor Mechanisms in Chronic Hypoxia-Induced Pulmonary Hypertension: Role of Oxidant Signaling". Antioxidants 9, n.º 10 (15 de outubro de 2020): 999. http://dx.doi.org/10.3390/antiox9100999.
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Elevated resistance of pulmonary circulation after chronic hypoxia exposure leads to pulmonary hypertension. Contributing to this pathological process is enhanced pulmonary vasoconstriction through both calcium-dependent and calcium sensitization mechanisms. Reactive oxygen species (ROS), as a result of increased enzymatic production and/or decreased scavenging, participate in augmentation of pulmonary arterial constriction by potentiating calcium influx as well as activation of myofilament sensitization, therefore mediating the development of pulmonary hypertension. Here, we review the effects of chronic hypoxia on sources of ROS within the pulmonary vasculature including NADPH oxidases, mitochondria, uncoupled endothelial nitric oxide synthase, xanthine oxidase, monoamine oxidases and dysfunctional superoxide dismutases. We also summarize the ROS-induced functional alterations of various Ca2+ and K+ channels involved in regulating Ca2+ influx, and of Rho kinase that is responsible for myofilament Ca2+ sensitivity. A variety of antioxidants have been shown to have beneficial therapeutic effects in animal models of pulmonary hypertension, supporting the role of ROS in the development of pulmonary hypertension. A better understanding of the mechanisms by which ROS enhance vasoconstriction will be useful in evaluating the efficacy of antioxidants for the treatment of pulmonary hypertension.
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Behringer, Erik, e Md Hakim. "Functional Interaction among KCa and TRP Channels for Cardiovascular Physiology: Modern Perspectives on Aging and Chronic Disease". International Journal of Molecular Sciences 20, n.º 6 (19 de março de 2019): 1380. http://dx.doi.org/10.3390/ijms20061380.
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Effective delivery of oxygen and essential nutrients to vital organs and tissues throughout the body requires adequate blood flow supplied through resistance vessels. The intimate relationship between intracellular calcium ([Ca2+]i) and regulation of membrane potential (Vm) is indispensable for maintaining blood flow regulation. In particular, Ca2+-activated K+ (KCa) channels were ascertained as transducers of elevated [Ca2+]i signals into hyperpolarization of Vm as a pathway for decreasing vascular resistance, thereby enhancing blood flow. Recent evidence also supports the reverse role for KCa channels, in which they facilitate Ca2+ influx into the cell interior through open non-selective cation (e.g., transient receptor potential; TRP) channels in accord with robust electrical (hyperpolarization) and concentration (~20,000-fold) transmembrane gradients for Ca2+. Such an arrangement supports a feed-forward activation of Vm hyperpolarization while potentially boosting production of nitric oxide. Furthermore, in vascular types expressing TRP channels but deficient in functional KCa channels (e.g., collecting lymphatic endothelium), there are profound alterations such as downstream depolarizing ionic fluxes and the absence of dynamic hyperpolarizing events. Altogether, this review is a refined set of evidence-based perspectives focused on the role of the endothelial KCa and TRP channels throughout multiple experimental animal models and vascular types. We discuss the diverse interactions among KCa and TRP channels to integrate Ca2+, oxidative, and electrical signaling in the context of cardiovascular physiology and pathology. Building from a foundation of cellular biophysical data throughout a wide and diverse compilation of significant discoveries, a translational narrative is provided for readers toward the treatment and prevention of chronic, age-related cardiovascular disease.
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Bett, Glenna C. L. "Hormones and sex differences: changes in cardiac electrophysiology with pregnancy". Clinical Science 130, n.º 10 (1 de abril de 2016): 747–59. http://dx.doi.org/10.1042/cs20150710.
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Disruption of cardiac electrical activity resulting in palpitations and syncope is often an early symptom of pregnancy. Pregnancy is a time of dramatic and dynamic physiological and hormonal changes during which numerous demands are placed on the heart. These changes result in electrical remodelling which can be detected as changes in the electrocardiogram (ECG). This gestational remodelling is a very under-researched area. There are no systematic large studies powered to determine changes in the ECG from pre-pregnancy, through gestation, and into the postpartum period. The large variability between patients and the dynamic nature of pregnancy hampers interpretation of smaller studies, but some facts are consistent. Gestational cardiac hypertrophy and a physical shift of the heart contribute to changes in the ECG. There are also electrical changes such as an increased heart rate and lengthening of the QT interval. There is an increased susceptibility to arrhythmias during pregnancy and the postpartum period. Some changes in the ECG are clearly the result of changes in ion channel expression and behaviour, but little is known about the ionic basis for this electrical remodelling. Most information comes from animal models, and implicates changes in the delayed-rectifier channels. However, it is likely that there are additional roles for sodium channels as well as changes in calcium homoeostasis. The changes in the electrical profile of the heart during pregnancy and the postpartum period have clear implications for the safety of pregnant women, but the field remains relatively undeveloped.
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Fritz, Elsa, Pamela Izaurieta, Alexandra Weiss, Franco R. Mir, Patricio Rojas, David Gonzalez, Fabiola Rojas, Robert H. Brown, Rodolfo Madrid e Brigitte van Zundert. "Mutant SOD1-expressing astrocytes release toxic factors that trigger motoneuron death by inducing hyperexcitability". Journal of Neurophysiology 109, n.º 11 (1 de junho de 2013): 2803–14. http://dx.doi.org/10.1152/jn.00500.2012.
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Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by dysfunction and degeneration of motoneurons starting in adulthood. Recent studies using cell or animal models document that astrocytes expressing disease-causing mutations of human superoxide dismutase 1 (hSOD1) contribute to the pathogenesis of ALS by releasing a neurotoxic factor(s). Neither the mechanism by which this neurotoxic factor induces motoneuron death nor its cellular site of action has been elucidated. Here we show that acute exposure of primary wild-type spinal cord cultures to conditioned medium derived from astrocytes expressing mutant SOD1 (ACM-hSOD1G93A) increases persistent sodium inward currents (PCNa), repetitive firing, and intracellular calcium transients, leading to specific motoneuron death days later. In contrast to TTX, which paradoxically increased twofold the amplitude of calcium transients and killed motoneurons, reduction of hyperexcitability by other specific (mexiletine) and nonspecific (spermidine and riluzole) blockers of voltage-sensitive sodium (Nav) channels restored basal calcium transients and prevented motoneuron death induced by ACM-hSOD1G93A. These findings suggest that riluzole, the only FDA-approved drug with known benefits for ALS patients, acts by inhibiting hyperexcitability. Together, our data document that a critical element mediating the non-cell-autonomous toxicity of ACM-hSOD1G93A on motoneurons is increased excitability, an observation with direct implications for therapy of ALS.
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Góra, Małgorzata, Anna Czopek, Anna Rapacz, Anna Dziubina, Monika Głuch-Lutwin, Barbara Mordyl e Jolanta Obniska. "Synthesis, Anticonvulsant and Antinociceptive Activity of New Hybrid Compounds: Derivatives of 3-(3-Methylthiophen-2-yl)-pyrrolidine-2,5-dione". International Journal of Molecular Sciences 21, n.º 16 (11 de agosto de 2020): 5750. http://dx.doi.org/10.3390/ijms21165750.
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The present study aimed to design and synthesize a new series of hybrid compounds with pyrrolidine-2,5-dione and thiophene rings in the structure as potential anticonvulsant and antinociceptive agents. For this purpose, we obtained a series of new compounds and evaluated their anticonvulsant activity in animal models of epilepsy (maximal electroshock (MES), psychomotor (6 Hz), and subcutaneous pentylenetetrazole (scPTZ) seizure tests). To determine the mechanism of action of the most active anticonvulsant compounds (3, 4, 6, 9), their influence on the voltage-gated sodium and calcium channels as well as GABA transporter (GAT) was assessed. The most promising compound 3-(3-methylthiophen-2-yl)-1-(3-morpholinopropyl)pyrrolidine-2,5-dione hydrochloride (4) showed higher ED50 value than those of the reference drugs: valproic acid (VPA) and ethosuximide (ETX) (62.14 mg/kg vs. 252.7 mg/kg (VPA) in the MES test, and 75.59 mg/kg vs. 130.6 mg/kg (VPA) and 221.7 mg/kg (ETX) in the 6 Hz test, respectively). Moreover, in vitro studies of compound 4 showed moderate but balanced inhibition of the neuronal voltage-sensitive sodium (site 2) and L-type calcium channels. Additionally, the antinociceptive activity of the most active compounds (3, 4, 6, 9) was also evaluated in the hot plate test and writhing tests, and their hepatotoxic properties in HepG2 cells were also investigated. To determine the possible mechanism of the analgesic effect of compounds 3, 6, and 9, the affinity for the TRPV1 receptor was investigated.
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Khaleel, Anas, Mei-Shin Wu, Henry Sung-Ching Wong, Yu-Wen Hsu, Yii-Her Chou e Hsiang-Yin Chen. "A Single Nucleotide Polymorphism (rs4236480) inTRPV5Calcium Channel Gene Is Associated with Stone Multiplicity in Calcium Nephrolithiasis Patients". Mediators of Inflammation 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/375427.
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Nephrolithiasis is characterized by calcification of stones in the kidneys from an unknown cause. Animal models demonstrated the functional roles of the transient receptor potential vanilloid member 5 (TRPV5) gene in calcium renal reabsorption and hypercalciuria. Therefore,TRPV5was suggested to be involved in calcium homeostasis. However, whether genetic polymorphisms ofTRPV5are associated with kidney stone multiplicity or recurrence is unclear. In this study, 365 Taiwanese kidney-stone patients were recruited. Both biochemical data and DNA samples were collected. Genotyping was performed by a TaqMan allelic discrimination assay. We found that aTRPV5polymorphism (rs4236480) was observed to be associated with stone multiplicity of calcium nephrolithiasis, as the risk of stone multiplicity was higher in patients with the TT+CT genotype than in patients with the CC genotype(p=0.0271). In summary, despite the complexity of nephrolithiasis and the potential association of numerous calcium homeostatic absorption/reabsorption factors,TRPV5plays an important role in the pathogenesis of calcium nephrolithiasis.
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Burmeister, David, Tamer AbouShwareb, Ralph D'Agostino, Karl-Erik Andersson e George J. Christ. "Impact of partial urethral obstruction on bladder function: time-dependent changes and functional correlates of altered expression of Ca2+ signaling regulators". American Journal of Physiology-Renal Physiology 302, n.º 12 (15 de junho de 2012): F1517—F1528. http://dx.doi.org/10.1152/ajprenal.00016.2012.
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In animal models of partial urethral obstruction (PUO), altered smooth muscle function/contractility may be linked to changes in molecules that regulate calcium signaling/sensitization. PUO was created in male rats, and urodynamic studies were conducted 2 and 6 wk post-PUO. Cystometric recordings were analyzed for the presence or absence of nonvoiding contractions [i.e., detrusor overactivity (DO)]. RT-PCR and Western blots were performed on a subpopulation of rats to study the relationship between the expression of RhoA, L-type Ca2+ channels, Rho kinase-1, Rho kinase-2, inositol 1,4,5-trisphosphate, ryanodine receptor, sarco(endo)plasmic reticulum Ca2+-ATPase 2 and protein kinase C (PKC)-potentiated phosphatase inhibitor of 17 kDa, and urodynamic findings in the same animal. Animals displayed DO at 2 (38%) and 6 wk (43%) post-PUO, increases were seen in in vivo pressures at 2 wk, and residual volume at 6 wk. Statistical analysis of RT-PCR and Western blot data at 2 wk, during the compensatory phase of detrusor hypertrophy, documented that expression of molecules that regulate calcium signaling and sensitization was consistently lower in obstructed rats without DO than those with DO or control rats. Among rats with DO at 2 wk, linear regression analysis revealed positive correlations between in vivo pressures and protein and mRNA expression of several regulatory molecules. At 6 wk, in the presence of overt signs of bladder decompensation, no clear or consistent alterations in expression of these same targets were observed at the protein level. These data extend prior work to suggest that molecular profiling of key regulatory molecules during the progression of PUO-mediated bladder dysfunction may shed new light on potential biomarkers and/or therapeutic targets.
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Cáceres-Chávez, Verónica Alejandra, Ricardo Hernández-Martínez, Jesús Pérez-Ortega, Marco Arieli Herrera-Valdez, Jose J. Aceves, Elvira Galarraga e José Bargas. "Acute dopamine receptor blockade in substantia nigra pars reticulata: a possible model for drug-induced Parkinsonism". Journal of Neurophysiology 120, n.º 6 (1 de dezembro de 2018): 2922–38. http://dx.doi.org/10.1152/jn.00579.2018.
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Dopamine (DA) depletion modifies the firing pattern of neurons in the substantia nigra pars reticulata (SNr), shifting their mostly tonic firing toward irregularity and bursting, traits of pathological firing underlying rigidity and postural instability in Parkinson’s disease (PD) patients and animal models of Parkinsonism (PS). Drug-induced Parkinsonism (DIP) represents 20–40% of clinical cases of PS, becoming a problem for differential diagnosis, and is still not well studied with physiological tools. It may co-occur with tardive dyskinesia. Here we use in vitro slice preparations including the SNr to observe drug-induced pathological firing by using drugs that most likely produce it, DA-receptor antagonists (SCH23390 plus sulpiride), to compare with firing patterns found in DA-depleted tissue. The hypothesis is that SNr firing would be similar under both conditions, a prerequisite to the proposal of a similar preparation to test other DIP-producing drugs. Firing was analyzed with three complementary metrics, showing similarities between DA depletion and acute DA-receptor blockade. Moreover, blockade of either nonselective cationic channels or Cav3 T-type calcium channels hyperpolarized the membrane and abolished bursting and irregular firing, silencing SNr neurons in both conditions. Therefore, currents generating firing in control conditions are in part responsible for pathological firing. Haloperidol, a DIP-producing drug, reproduced DA-receptor antagonist firing modifications. Since acute DA-receptor blockade induces SNr neuron firing similar to that found in the 6-hydroxydopamine model of PS, output basal ganglia neurons may play a role in generating DIP. Therefore, this study opens the way to test other DIP-producing drugs. NEW & NOTEWORTHY Dopamine (DA) depletion enhances substantia nigra pars reticulata (SNr) neuron bursting and irregular firing, hallmarks of Parkinsonism. Several drugs, including antipsychotics, antidepressants, and calcium channel antagonists, among others, produce drug-induced Parkinsonism. Here we show the first comparison between SNr neuron firing after DA depletion vs. firing found after acute blockade of DA receptors. It was found that firing in both conditions is similar, implying that pathological SNr neuron firing is also a physiological correlate of drug-induced Parkinsonism.
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Laher, Ismail, e John H. Zhang. "Protein Kinase C and Cerebral Vasospasm". Journal of Cerebral Blood Flow & Metabolism 21, n.º 8 (agosto de 2001): 887–906. http://dx.doi.org/10.1097/00004647-200108000-00001.
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Twenty-five years after the discovery of protein kinase C (PKC), the physiologic function of PKC, and especially its role in pathologic conditions, remains a subject of great interest with 30,000 studies published on these aspects. In the cerebral circulation, PKC plays a role in the regulation of myogenic tone by sensitization of myofilaments to calcium. Protein kinase C phosphorylates various ion channels including augmenting voltage-dependent Ca2+ channels and inhibiting K+ channels, which both lead to vessel contraction. These actions of PKC amplify vascular reactivity to different agonists and may be critical in the regulation of cerebral artery tone during vasospasm. Evidence accumulated during at least the last decade suggest that activation of PKC in cerebral vasospasm results in a delayed but prolonged contraction of major arteries after subarachnoid hemorrhage. Most of the experimental results in vitro or in animal models support the view that PKC is involved in cerebral vasospasm. Implication of PKC in cerebral vasospasm helps explain increased arterial narrowing at the signal transduction level and alters current perceptions that the pathophysiology is caused by a combination of multiple receptor activation, hemoglobin toxicity, and damaged neurogenic control. Activation of protein kinase C also interacts with other signaling pathways such as myosin light chain kinase, nitric oxide, intracellular Ca2+, protein tyrosine kinase, and its substrates such as mitogen-activated protein kinase. Even though identifying PKC revolutionized the understanding of cerebral vasospasm, clinical advances are hampered by the lack of clinical trials using selective PKC inhibitors.
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Martac, Ljiljana. "Fractal dimension and neurotoxicity in rats intoxicated by aluminium". Veterinarski glasnik 69, n.º 1-2 (2015): 21–29. http://dx.doi.org/10.2298/vetgl1502021m.
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We used animal model of neurotoxicity in rats, which provided the possibility of studying biological pathophysiological phenomena in vivo and afterwards in vitro conditions. The analysis of electrocortical brain activity using mathematical methods can describe the changes induced by aluminum intoxication in rat as an animal model. In physiological and pathophysiological conditions, on experimental models, mechanisms related to changes in behavior, plasticity and accumulation of aluminum in nervous tissue of the rat brain were observed. Animal models of rats used in the experiments described changes in the group of neuronal activity in the brain of rats in different modes of intoxication aluminum. This study describes ECoG activity in the brain of rats under anesthesia in both the control and aluminum treated animals. Fractal and spectral analysis was used to present qualitative and quantitative changes in the conditions of neurotoxicity. Changes in neurotransmission, as well as the structure and function of the neural network are connected to the molecular-physiological mechanisms of neurotoxicity. Aluminium toxicity was monitored through changes in glutamatergic activity and calcium channel activity. By spectrum analysis neurotoxicity was described through changes in spectral power in the corresponding frequency ranges. By comparing the FD of intoxicated and control individuals there was obtained the range of the change in correlation with the corresponding pathophysiological conditions of intoxication. The shange in FD might be an indication of neurotoxicity.
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Shi, Yun, Yong Wang e Huafeng Wei. "Dantrolene : From Malignant Hyperthermia to Alzheimer’s Disease". CNS & Neurological Disorders - Drug Targets 18, n.º 9 (15 de janeiro de 2020): 668–76. http://dx.doi.org/10.2174/1871527317666180619162649.
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Dantrolene, a ryanodine receptor antagonist, is primarily known as the only clinically acceptable and effective treatment for Malignant Hyperthermia (MH). Inhibition of Ryanodine Receptor (RyR) by dantrolene decreases the abnormal calcium release from the Sarcoplasmic Reticulum (SR) or Endoplasmic Reticulum (ER), where RyR is located. Recently, emerging researches on dissociated cells, brains slices, live animal models and patients have demonstrated that altered RyR expression and function can also play a vital role in the pathogenesis of Alzheimer’s Disease (AD). Therefore, dantrolene is now widely studied as a novel treatment for AD, targeting the blockade of RyR channels or another alternative pathway, such as the inhibitory effects of NMDA glutamate receptors and the effects of ER-mitochondria connection. However, the therapeutic effects are not consistent. In this review, we focus on the relationship between the altered RyR expression and function and the pathogenesis of AD, and the potential application of dantrolene as a novel treatment for the disease.
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Cussac, Laure-Anne, Guillaume Cardouat, Nichiren Tiruchellvam Pillai, Marilyne Campagnac, Paul Robillard, Anaïs Montillaud, Christelle Guibert et al. "TRPV4 channel mediates adventitial fibroblast activation and adventitial remodeling in pulmonary hypertension". American Journal of Physiology-Lung Cellular and Molecular Physiology 318, n.º 1 (1 de janeiro de 2020): L135—L146. http://dx.doi.org/10.1152/ajplung.00084.2019.
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Pulmonary arterial adventitial fibroblasts (PAF), the most abundant cellular constituent of adventitia, act as a key regulator of pulmonary vascular wall structure and function from the outside-in. Previous studies indicate that transient receptor potential vanilloid 4 (TRPV4) channel plays an important role in the development of pulmonary hypertension (PH), but no attention has been given so far to its role in adventitial remodeling. In this study, we thus investigated TRPV4 implication in PAF activation occurring in PH. First, we isolated and cultured PAF from rat adventitial intrapulmonary artery. RT-PCR, Western blot, immunostaining, and calcium imaging (fluo-4/AM) showed that PAF express functional TRPV4 channels. In extension of these results, using pharmacological and siRNA approaches, we demonstrated TRPV4 involvement in PAF proliferation (BrdU incorporation) and migration (wound-healing assay). Then, Western blot experiments revealed that TRPV4 activation upregulates the expression of extracellular matrix protein synthesis (collagen type I and fibronectin). Finally, we explored the role of TRPV4 in the adventitial remodeling occurring in PH. By means of Western blot, we determined that TRPV4 protein expression was upregulated in adventitia from chronically hypoxic and monocrotaline rats, two animal models of PH. Furthermore, morphometric analysis indicated that adventitial remodeling is attenuated in PH-induced trpv4−/− mice. These data support the concept that PAF play an essential role in hypertensive pulmonary vascular remodeling and point out the participation of TRPV4 channel activity in PAF activation leading to excessive adventitial remodeling.
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Kim, Galina A., Tamara S. Gan’shina, Elena V. Kurza, Ilya N. Kurdyumov, Denis V. Maslennikov e Ruben S. Mirzoian. "New cerebrovascular agent with hypotensive activity". Research Results in Pharmacology 5, n.º 2 (27 de junho de 2019): 71–77. http://dx.doi.org/10.3897/rrpharmacology.5.35392.
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Introduction: In cerebrovascular disorders, special attention is paid to a hypertensive cerebrovascular crisis, which combines a vascular injury of the brain and hypertension. The paper studies the cerebrovascular properties of the calcium channel blocker of S-Amlodipine nicotinate antihypertensive agent. Materials and methods: Tests were performed on 96 nonlinear male rats, measuring local blood flow in the cerebral cortex in 36 awake animals, using a laser Doppler flowmeter. Cerebral circulation was recorded in the animals when modeling ischemic and hemorrhagic brain injuries. Results and discussion: S-Amlodipine nicotinate (0.1 mg/kg i/v) shows a pronounced cerebrovascular activity in the models of ischemic and hemorrhagic injuries of the brain. In terms of the vasodilating effect in ischemic brain injury, the drug is comparable to mexidol, nimodipine, picamilon, but is superior to nimodipine and picamilon in terms of duration of action, and in the model of hemorrhagic stroke, S-Amlodipine nicotinate is superior to nimodipine and is comparable to picamilon and mexidol. The analysis of the mechanism of action of the agent revealed the participation of GABA A-receptors in the implementation of cerebrovascular properties of the agent. Conclusion: Significant cerebrovascular activity of S-Amlodipine nicotinate (0.1 mg/kg i/v) antihypertensive agent was revealed. The presence of GABAergic mechanism on cerebral blood flow in the agent action along with blockade of slow calcium channels ensures its high efficacy in treatment of both ischemic and hemorrhagic brain injuries.
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Yoder, Bradley K., Sharon Mulroy, Hannah Eustace, Catherine Boucher e Richard Sandford. "Molecular pathogenesis of autosomal dominant polycystic kidney disease". Expert Reviews in Molecular Medicine 8, n.º 2 (17 de janeiro de 2006): 1–22. http://dx.doi.org/10.1017/s1462399406010362.
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Autosomal dominant polycystic kidney disease (ADPKD) is one of the commonest inherited human disorders yet remains relatively unknown to the wider medical, scientific and public audience. ADPKD is characterised by the development of bilateral enlarged kidneys containing multiple fluid-filled cysts and is a leading cause of end-stage renal failure (ESRF). ADPKD is caused by mutations in two genes: PKD1 and PKD2. The protein products of the PKD genes, polycystin-1 and polycystin-2, form a calcium-regulated, calcium-permeable ion channel. The polycystin complex is implicated in regulation of the cell cycle via multiple signal transduction pathways as well as the mechanosensory function of the renal primary cilium, an enigmatic cellular organelle whose role in normal physiology is still poorly understood. Defects in cilial function are now documented in several other human diseases including autosomal recessive polycystic kidney disease, nephronophthisis, Bardet–Biedl syndrome and many animal models of polycystic kidney disease. Therapeutic trials in these animal models of polycystic kidney disease have identified several promising drugs that ameliorate disease severity. However, elucidation of the function of the polycystins and the primary cilium will have a major impact on our understanding of renal cystic diseases and will create exciting new opportunities for the design of disease-specific therapies.
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Khan, Mohd Muazzam, Badruddeen, Mohd Mujahid, Juber Akhtar, Mohammad Irfan Khan e Usama Ahmad. "An Overview of Stroke: Mechanism, In vivo Experimental Models Thereof, and Neuroprotective Agents". Current Protein & Peptide Science 21, n.º 9 (11 de dezembro de 2020): 860–77. http://dx.doi.org/10.2174/1389203721666200617133903.
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Background: Stroke is one of the causes of death and disability globally. Brain attack is because of the acute presentation of stroke, which highlights the requirement for decisive action to treat it. Objective: The mechanism and in-vivo experimental models of stroke with various neuroprotective agents are highlighted in this review. Method: The damaging mechanisms may proceed by rapid, nonspecific cell lysis (necrosis) or by the active form of cell death (apoptosis or necroptosis), depending upon the duration and severity and of the ischemic insult. Results: Identification of injury mediators and pathways in a variety of experimental animal models of global cerebral ischemia has directed to explore the target-specific cytoprotective strategies, which are critical to clinical brain injury outcomes. Conclusion: The injury mechanism, available encouraging medicaments thereof, and outcomes of natural and modern medicines for ischemia have been summarized. In spite of available therapeutic agents (thrombolytics, calcium channel blockers, NMDA receptor antagonists and antioxidants), there is a need for an ideal drug for strokes.
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Bauer, Claudia S., Wahida Rahman, Alexandra Tran-Van-Minh, Rafael Lujan, Anthony H. Dickenson e Annette C. Dolphin. "The anti-allodynic α2δ ligand pregabalin inhibits the trafficking of the calcium channel α2δ-1 subunit to presynaptic terminals in vivo". Biochemical Society Transactions 38, n.º 2 (22 de março de 2010): 525–28. http://dx.doi.org/10.1042/bst0380525.
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Neuropathic pain is caused by lesion or dysfunction of the peripheral sensory nervous system. Up-regulation of the voltage-gated Ca2+ channel subunit α2δ-1 in DRG (dorsal root ganglion) neurons and the spinal cord correlates with the onset of neuropathic pain symptoms such as allodynia in several animal models of neuropathic pain. The clinically important anti-allodynic drugs gabapentin and pregabalin are α2δ-1 ligands, but how these drugs alleviate neuropathic pain is poorly understood. In the present paper, we review recent advances in our understanding of their molecular mechanisms.
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Fan, Youjia, Gaici Xue, Qianbo Chen, Ye Lu, Rong Dong e Hongbin Yuan. "CY-09 Inhibits NLRP3 Inflammasome Activation to Relieve Pain via TRPA1". Computational and Mathematical Methods in Medicine 2021 (14 de agosto de 2021): 1–10. http://dx.doi.org/10.1155/2021/9806690.
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Peripheral tissue damage leads to inflammatory pain, and inflammatory cytokine releasing is the key factor for inducing the sensitization of nociceptors. As a calcium ion channel, TRPA1 plays an important role in pain and inflammation, thus becoming a new type of anti-inflammatory and analgesic target. However, there is no consensus on the role of this channel in mechanical hyperalgesia caused by inflammation. Here, we aim to explore the role and underlying mechanism of the inflammasome inhibitor CY-09 in two classic inflammatory pain models. We evaluated pain behavior on animal models, cytokine levels, intracellular Ca2+ levels, transient TRPA1 expression, NF-κB transcription, and NLPR3 inflammasome activation. Consistently, CY-09 reduced the production of inflammatory cytokines, intracellular Ca2+ levels, and the activation of TRPA1 by inhibiting the activation of inflammasomes, thereby reducing the proinflammatory polarization of macrophages and alleviating animal pain and injury. Importantly, AITC (TRPA1 agonist) significantly reversed the analgesic effect of CY-09, indicating that TRPA1 was involved in the analgesic effect of CY-09. Our findings indicate that CY-09 relieves inflammation and pain via inhibiting TRPA1-mediated activation of NLRP3 inflammasomes. Thus, NLRP3 inflammasome may be a potential therapeutic target for pain treatment and CY-09 may be a pharmacological agent to relieve inflammatory pain, which needs further research.
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Ma, Di, Liangshu Feng, Fang Deng e Jia-Chun Feng. "Overview of Experimental and Clinical Findings regarding the Neuroprotective Effects of Cerebral Ischemic Postconditioning". BioMed Research International 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/6891645.
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Research on attenuating the structural and functional deficits observed following ischemia-reperfusion has become increasingly focused on the therapeutic potential of ischemic postconditioning. In recent years, various methods and animal models of ischemic postconditioning have been utilized. The results of these numerous studies have indicated that the mechanisms underlying the neuroprotective effects of ischemic postconditioning may involve reductions in the generation of free radicals and inhibition of calcium overload, as well as the release of endogenous active substances, alterations in membrane channel function, and activation of protein kinases. Here we review the novel discovery, mechanism, key factors, and clinical application of ischemic postconditioning and discuss its implications for future research and problem of clinical practice.
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Felberg, Robert A., W. Scott Burgin e James C. Grotta. "Neuroprotection and the Ischemic Cascade". CNS Spectrums 5, n.º 3 (março de 2000): 52–58. http://dx.doi.org/10.1017/s1092852900012967.
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AbstractBrain ischemia is a process of delayed neuronal cell death, not an instantaneous event. The concept of neuroprotection is based on this principle. Diminished cerebral blood flow initiates a series of events (the “ischemic cascade”) that lead to cell destruction. This ischemic cascade is akin to a spreading epidemic starting from a hypothesized core of ischemia and radiating outward. If intervention occurs early, the process may be halted.Interventions have been directed toward salvaging the ischemic penumbra. Hypothermia decreases the size of the ischemic insult in both anecdotal clinical and laboratory reports. In addition, a wide variety of agents have been shown to reduce infant volume in animal models. Pharmacologic interventions that involve thrombolysis, calcium channel blockade, and cell membrane receptor antagonism have been studied and have been found to be beneficial in animal cortical stroke models. Human trials of neuroprotective therapies have been disappointing. Other than thrombolytics, no agents, have shown an unequivocal benefit. The future of neuroprotection will require a logical extension of what has been learned in the laboratory and previous human trials. A sensible approach to the use of multiple-agent cocktails used in combination with thrombolytics is likely to offer the highest chance for benefit.
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Simard, J. Marc, S. Kyoon Woo, Gary T. Schwartzbauer e Volodymyr Gerzanich. "Sulfonylurea Receptor 1 in Central Nervous System Injury: A Focused Review". Journal of Cerebral Blood Flow & Metabolism 32, n.º 9 (20 de junho de 2012): 1699–717. http://dx.doi.org/10.1038/jcbfm.2012.91.
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The sulfonylurea receptor 1 (Sur1)-regulated NCCa-ATP channel is a nonselective cation channel that is regulated by intracellular calcium and adenosine triphosphate. The channel is not constitutively expressed, but is transcriptionally upregulated de novo in all cells of the neurovascular unit, in many forms of central nervous system (CNS) injury, including cerebral ischemia, traumatic brain injury (TBI), spinal cord injury (SCI), and subarachnoid hemorrhage (SAH). The channel is linked to microvascular dysfunction that manifests as edema formation and delayed secondary hemorrhage. Also implicated in oncotic cell swelling and oncotic (necrotic) cell death, the channel is a major molecular mechanism of ‘accidental necrotic cell death’ in the CNS. In animal models of SCI, pharmacological inhibition of Sur1 by glibenclamide, as well as gene suppression of Abcc8, prevents delayed capillary fragmentation and tissue necrosis. In models of stroke and TBI, glibenclamide ameliorates edema, secondary hemorrhage, and tissue damage. In a model of SAH, glibenclamide attenuates the inflammatory response due to extravasated blood. Clinical trials of an intravenous formulation of glibenclamide in TBI and stroke underscore the importance of recent advances in understanding the role of the Sur1-regulated NCCa-ATP channel in acute ischemic, traumatic, and inflammatory injury to the CNS.
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Chen, Guangping, Yuan Yang, Otto Fröhlich, Janet D. Klein e Jeff M. Sands. "Suppression subtractive hybridization analysis of low-protein diet- and vitamin D-induced gene expression from rat kidney inner medullary base". Physiological Genomics 41, n.º 3 (maio de 2010): 203–11. http://dx.doi.org/10.1152/physiolgenomics.00129.2009.
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Protein restriction and hypercalcemia result in a urinary concentrating defect in rats and humans. Previous tubular perfusion studies show that there is an increased active urea transport activity in the initial inner medullary (IM) collecting duct in low-protein diet (LPD) and vitamin D (Vit D) animal models. To investigate the possible mechanisms that cause the urinary concentrating defect and to clone the new active urea transporter, we employed a modified two-tester suppression subtractive hybridization (ttSSH) approach and examined gene expression induced by LPD and Vit D in kidney IM base. Approximately 600 clones from the subtracted library were randomly selected; 150 clones were further confirmed to be the true positive genes by slot blot hybridization with subtracted probes from LPD and Vit D and sent for DNA sequencing. We identified 10 channel/transporter genes that were upregulated in IM base in LPD and Vit D animal models; 8 were confirmed by real-time PCR. These genes include aquaporin 2 (AQP2), two-pore calcium channel protein 2, brain-specific organic cation transporter, Na+- and H+-coupled glutamine transporter, and solute carrier family 25. Nine genes are totally new, and twelve are uncharacterized hypothetical proteins. Among them, four genes were shown to be new transmembrane proteins as judged by Kyte-Doolittle hydrophobic plot analysis. ttSSH provides a useful method to identify new genes from two conditioned populations.
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Bocchi, Leonardo, Monia Savi, Valeria Naponelli, Rocchina Vilella, Gianluca Sgarbi, Alessandra Baracca, Giancarlo Solaini, Saverio Bettuzzi, Federica Rizzi e Donatella Stilli. "Long-Term Oral Administration of Theaphenon-E Improves Cardiomyocyte Mechanics and Calcium Dynamics by Affecting Phospholamban Phosphorylation and ATP Production". Cellular Physiology and Biochemistry 47, n.º 3 (2018): 1230–43. http://dx.doi.org/10.1159/000490219.
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Background/Aims: Dietary polyphenols from green tea have been shown to possess cardio-protective activities in different experimental models of heart diseases and age-related ventricular dysfunction. The present study was aimed at evaluating whether long term in vivo administration of green tea extracts (GTE), can exert positive effects on the normal heart, with focus on the underlying mechanisms. Methods: The study population consisted of 20 male adult Wistar rats. Ten animals were given 40 mL/day tap water solution of GTE (concentration 0.3%) for 4 weeks (GTE group). The same volume of water was administered to the 10 remaining control rats (CTRL). Then, in vivo and ex vivo measurements of cardiac function were performed in the same animal, at the organ (hemodynamics) and cellular (cardiomyocyte mechanical properties and intracellular calcium dynamics) levels. On cardiomyocytes and myocardial tissue samples collected from the same in vivo studied animals, we evaluated: (1) the intracellular content of ATP, (2) the endogenous mitochondrial respiration, (3) the expression levels of the Sarcoplasmic Reticulum Ca2+-dependent ATPase 2a (SERCA2), the Phospholamban (PLB) and the phosphorylated form of PLB, the L-type Ca2+ channel, the Na+-Ca2+ exchanger, and the ryanodine receptor 2. Results: GTE cardiomyocytes exhibited a hyperdynamic contractility compared with CTRL (the rate of shortening and re-lengthening, the fraction of shortening, the amplitude of calcium transient, and the rate of cytosolic calcium removal were significantly increased). A faster isovolumic relaxation was also observed at the organ level. Consistent with functional data, we measured a significant increase in the intracellular ATP content supported by enhanced endogenous mitochondrial respiration in GTE cardiomyocytes, as well as higher values of the ratios phosphorylated-PLB/PLB and SERCA2/PLB. Conclusions: Long-term in vivo administration of GTE improves cell mechanical properties and intracellular calcium dynamics in normal cardiomyocytes, by increasing energy availability and removing the inhibitory effect of PLB on SERCA2.
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Abram, Michał, Marcin Jakubiec, Anna Rapacz, Szczepan Mogilski, Gniewomir Latacz, Rafał M. Kamiński e Krzysztof Kamiński. "The Search for New Anticonvulsants in a Group of (2,5-Dioxopyrrolidin-1-yl)(phenyl)Acetamides with Hybrid Structure—Synthesis and In Vivo/In Vitro Studies". International Journal of Molecular Sciences 21, n.º 22 (20 de novembro de 2020): 8780. http://dx.doi.org/10.3390/ijms21228780.
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Epilepsy belongs to the most common and debilitating neurological disorders with multifactorial pathophysiology and a high level of drug resistance. Therefore, with the aim of searching for new, more effective, and/or safer therapeutics, we discovered a focused series of original hybrid pyrrolidine-2,5-dione derivatives with potent anticonvulsant properties. We applied an optimized coupling reaction yielding several hybrid compounds that showed broad-spectrum activity in widely accepted animal seizure models, namely, the maximal electroshock (MES) test and the psychomotor 6 Hz (32 mA) seizure model in mice. The most potent anticonvulsant activity and favorable safety profile was demonstrated for compound 30 (median effective dose (ED50) MES = 45.6 mg/kg, ED50 6 Hz (32 mA) = 39.5 mg/kg, median toxic dose (TD50) (rotarod test) = 162.4 mg/kg). Anticonvulsant drugs often show activity in pain models, and compound 30 was also proven effective in the formalin test of tonic pain, the capsaicin-induced pain model, and the oxaliplatin (OXPT)-induced neuropathic pain model in mice. Our studies showed that the most plausible mechanism of action of 30 involves inhibition of calcium currents mediated by Cav1.2 (L-type) channels. Importantly, 30 revealed high metabolic stability on human liver microsomes, negligible hepatotoxicity, and relatively weak inhibition of CYP3A4, CYP2D6, and CYP2C9 isoforms of cytochrome P450, compared to reference compounds. The promising in vivo activity profile and drug-like properties of compound 30 make it an interesting candidate for further preclinical development.
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Swaminathan, Akila, Uma Maheswari Balaguru, Reji Manjunathan, Srinivasan Bhuvaneswari, Dharanibalan Kasiviswanathan, Bandi Sirishakalyani, Prasunpriya Nayak e Suvro Chatterjee. "Live Imaging and Analysis of Vasoactive Properties of Drugs Using an in-ovo Chicken Embryo Model: Replacing and Reducing Animal Testing". Microscopy and Microanalysis 25, n.º 4 (10 de maio de 2019): 961–70. http://dx.doi.org/10.1017/s1431927619000588.
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AbstractVasodilation occurs as a result of the relaxation of the smooth muscle cells present in the walls of blood vessels. Various suitable models are available for the analysis of the vasoactive properties of drugs with therapeutic applications. But all these models have limitations, such as ethical issues and high cost. The purpose of this study is to develop an alternative model for studying the vasoactive properties of drugs using an in-ovo chicken embryo model. In the preliminary experiment, we used a well-known vasoconstrictor (adrenaline) and a vasodilator (spermine NoNoate) in the chick embryo area vasculosa and evaluated their concentration-response curve. Adrenaline (10 µM) and spermine NoNoate (10 µM) were administered in different arteries and veins and different positions of the right vitelline artery of the chick embryo. Results showed the middle of the vessel bed of the right vitelline artery having the best vasoactive effect compared to others. Finally, anti-hypertensive drugs, calcium channel blockers, and NOS agonists were administered in the chick embryo area vasculosa to validate the model. Results demonstrate that the chick embryo area vasculosa can be an alternative, robust, and unique in-ovo model for screening of anti-hypertensive drugs in real time.
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Henry, Clémence O., Emilie Dalloneau, Maria-Teresa Pérez-Berezo, Cristina Plata, Yongzheng Wu, Antoine Guillon, Eric Morello et al. "In vitro and in vivo evidence for an inflammatory role of the calcium channel TRPV4 in lung epithelium: Potential involvement in cystic fibrosis". American Journal of Physiology-Lung Cellular and Molecular Physiology 311, n.º 3 (1 de setembro de 2016): L664—L675. http://dx.doi.org/10.1152/ajplung.00442.2015.
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Cystic fibrosis (CF) is an inherited disease associated with chronic severe lung inflammation, leading to premature death. To develop innovative anti-inflammatory treatments, we need to characterize new cellular and molecular components contributing to the mechanisms of lung inflammation. Here, we focused on the potential role of “transient receptor potential vanilloid-4” (TRPV4), a nonselective calcium channel. We used both in vitro and in vivo approaches to demonstrate that TRPV4 expressed in airway epithelial cells triggers the secretion of major proinflammatory mediators such as chemokines and biologically active lipids, as well as a neutrophil recruitment in lung tissues. We characterized the contribution of cytosolic phospholipase A2, MAPKs, and NF-κB in TRPV4-dependent signaling. We also showed that 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids, i.e., four natural lipid-based TRPV4 agonists, are present in expectorations of CF patients. Also, TRPV4-induced calcium mobilization and inflammatory responses were enhanced in cystic fibrosis transmembrane conductance regulator-deficient cellular and animal models, suggesting that TRPV4 is a promising target for the development of new anti-inflammatory treatments for diseases such as CF.