Dissertations / Theses on the topic 'Glutamate'
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Boulland, Jean-Luc. "Recycling the amino acid neurotransmitter glutamate in the CNS : l'alchimie du glutamate et de la glutamine." Paris 6, 2004. http://www.theses.fr/2004PA066017.
Full textCabré, Segura Gisela. "New photopharmacological tools for the light-induced control of neuronal signalling." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/668303.
Full textThe main objective of neuroscience is the study and control of neuronal systems. Nowadays, this area is being revolutionised by the use of photoresponsive small molecules, a field known as photopharmacology. By enabling remote activation of drugs with light, photopharmacology seeks to tackle some of the main challenges faced by conventional pharmacology, such as poor drug selectivity and side effects.1 Three main strategies have been derived in this area: photocaged ligands (CL), freely diffusing prodrugs the effect of which is triggered by removing photolabile protecting groups upon illumination; photochromic ligands (PCL), which allow reversible modulation of the response of bioactive molecules through photoisomerisation of appended light-responsive moieties; and photoswitched tethered ligands (PTL), a special case of PCLs that are covalently attached to the therapeutic receptor. Although these approaches have proven to be successful for a variety of therapeutic targets in vitro and in vivo, several challenges still remain in the field of photopharmacology. Therefore, in this work we have aimed at the investigation of new photopharmacological strategies that overcome some of the weaknesses of the tools developed so far. We have particularly focused on the photocontrol of ionotropic glutamate receptors (iGluRs), which play a key role in the modulation of neuronal excitability. The novel photopharmacological tools developed along this thesis consist in: (i) a PTL based on push-pull-substituted azobenzene photoswitches that responds to two-photon excitation with NIR light. (ii) a non-destructive caged ligand that enable irreversible and quantitative conversion from the inactive to the active state, thus performing in a similar fashion as CLs but without by-product generation. (iii) a PCL based on C2-bridged azobenzenes which displays a thermodynamically stable inactive form that selectively turns into the biologically-active state when irradiated. This thesis reports the synthesis, photochemical characterisation and biological activity evaluation of these three novel photopharmacological approaches.
Scott-Taggart, Catherine Patricia. "Inhibition of glutamine production increases glutamate metabolism via the GABA shunt." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ27542.pdf.
Full textBarel, Itai. "The regulation of glutamine synthetase and glutamate synthase in Schizosaccharomyces pombe." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279649.
Full textSilva, Jackeline Thaís da. "Aminoácidos limitantes para o desempenho de bezerros leiteiros: avaliação de teores ótimos e via de fornecimento." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-11112014-163521/.
Full textThe aim in this work was to evaluate the concentration of essential amino acids (Lysine and Methionine) considered in the literature as ideal, according to feeding route (milk replacer or starter concentrate), and its association with the supplementation of glutamate and glutamine to calves in two feeding systems: conventional or step-down. In the first study, the chemical composition was analyzed and in amino acids of main milk replacer marketed in Brazil. In the second and third studies, 45 Holstein calves were used, in randomized blocks distributed in treatments: 1) Control: without supplementation; 2) Supplementation with lysine and methionine to reach consumption of 17 and 5.3 g/d, respectively, with correction based on the analysis basis of the milk replacer, 3) Supplementation of lysine and methionine to reach consumption of 17 and 5.3 g/d, respectively, with correction based on the analysis basis of starter concentrate. The difference between the experiments was the feeding system applied to the calves: in the second study, the animals received 6 L/d of milk replacer; while in the third study, the animals were submitted to the step-down system (4L/d until the 2nd week; 8L/d of the 3nd to 6th week; 4L/d of the 7th to 8th week). In the fourth study, the same experimental design was used to evaluate, in a conventional feeding system, treatments: 1) Control: without supplementation; 2) AminoGut 0.6%: milk replacer supplemented with Lysine and Methionine, to reach consumption 17 and 5.3g/d, respectively + 0.6% product containing 10% of glutamate and glutamine; 3) AminoGut 1%: milk replacer supplemented with Lysine and Methionine to reach consumption 17 and 5.3g/d + 0.6% product containing 10% of glutamate and glutamine. The animals were housed in individual hutches, with free access to water and starter concentrate. The consumption of starter concentrate and fecal scores of animals were monitored daily. Body growth was weighed and measured weekly. In weeks 2, 4, 6, 8 and 10, blood samples were collected to determine the metabolites as markers of protein status of animals (albumin, total protein, N-urea), energy status (glucose and BHBA), bone growth (alkaline phosphatase) and muscular growth (creatinine). The composition of amino acids of the milk replacer marketed in Brazil was lower than expected for diet that replaces the whole milk. In study 2 and 3, the supplementation of the milk replacer or starter concentrate with lysine and methionine resulted in no benefit on dairy calves performance or metabolism. In study 4 the supplementation of the milk replacer with lysine and methionine in association with glutamate and glutmine had no effect on performance, gut health nor metabolism of dairy calves.
Apricò, Karina 1977. "[3H](2S,4R)-4-methylglutamate as a novel radioligand for brain glutamate transporters." Monash University, Dept. of Pharmacology, 2003. http://arrow.monash.edu.au/hdl/1959.1/5497.
Full textGirard, Benoît. "Impact de l’activation du récepteur mGlu7 dans l’épilepsie." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTT038.
Full textEpilepsy affects millions of patients worldwide. The available treatments are symptomatic, they treat seizures without preventing the progression of the disease and have heavy side effects. The discovery of new therapeutic targets and new compounds is therefore essential to overcome the limitations of current therapeutic strategies. Previous studies have demonstrated substantial involvement of the mGlu7 receptor in modulating not only excitability but also hypersynchronization of neural networks, two crucial factors affecting epileptic seizures. These discoveries were at the origin of a first publication that I completed at the beginning of my thesis (Tassin, Girard et al., 2016).Using a new mGlu7 receptor agonist, LSP2-9166, in my thesis I then studied the impact of this receptor in different epilepsy models in mice. Two complementary models were used: kindling, a chemical model induced by pentylenetetrazol (PTZ) which sensitizes the brain to induce generalized tonic-clonic seizures, and intra-hippocampal injection of kainate, mimicking mesial temporal lobe epilepsy in humans.At first, I observed an attenuation of the progression of the seizures severity in the PTZ kindling model, under the activation of the mGlu7 receptor. This effect was correlated with weaker inflammation, and microglial and astrocytic activation. In the intra-hippocampal injection model of KA, considered as drug-resistant, activation of the mGlu7 receptor during the epileptogenesis period increased the duration of interictal periods and decreased the duration of seizures as well as neuronal reorganization. Once chronic seizures were established, acute activation of the mGlu7 receptor decreased the number of seizures as strongly as diazepam, commonly used in clinical settings. Finally, chronic injections of LSP2-9166 into naive (non epileptic) animals do not generate any detectable cognitive or behavioral deficits or changes in mGlu7 receptor mRNA level. The activation of the mGlu7 receptor thus presents a strategic target in our two models.This work provides a better understanding of the role of the mGlu7 receptor in epileptogenesis. It participates in the search for future more adequate treatments
Sachidhanandam, Shankar. "Rôle des récepteurs kaïnate dans le transfert d'information dans l'hippocampe." Bordeaux 2, 2007. http://www.theses.fr/2007BOR21433.
Full textKainate receptors (KAR) are ionotropic glutamate receptors implicated in the regulation of synaptic transmission and neuronal excitability. At the mossy fiber (Mf) synapse, KARs can be expressed both pre and postsynaptically. In this study, we examined physiological role of KARs in information transfer at the Mf-CA3 pyramidal cell synapse in the mouse hippocampus. We show that KARs can operate in dual mode, by a direct ionotropic action via GluR6, and an indirect G-protein coupled mechanism requiring the binding of glutamate to KA2, to inhibit the slow afterhyperpolarization (IsAHP), hence enhancing neuronal excitability. Using mice deficient for the various KAR subunits, we show that postsynaptic KARs shape the waveform of unitary EPSPs, and pre and postsynaptic KARs act together to amplify unitary EPSPs, triggering spike discharge under conditions of sustained mossy fiber activity. KARs improve timing precision within a frequency range of 3 to 50 Hz and modulation of IsAHP by KA2 facilitates spike discharge in prolonged stimulus trains. KARs are permissive to the induction of LTP at the associative/commissural input. Physiological patterns of afferent input reproduce the output obtained with controlled stimulus inputs. Hence KARs act as amplifiers of synaptic transmission, to enhance the transfer of information at the Mf-CA3 pyramidal cell synapse
Martin, Emily P. "Expression of glutamate dehydrogenase and glutamine synthetase RNA in preimplantation mouse embryos." Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1117849.
Full textDepartment of Biology
Saito, Kelly Cristina. "Envolvimento de Rac1 na excitotoxicidade induzida por NMDA na retina de ratos." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-10022012-132908/.
Full textOveractivation of NMDA receptors has been described to trigger neuronal death that occurs in diseases such as glaucoma. It is possible that the combination of subunits (NR2A-D) activate intracellular signaling pathways that result in death or survival. Our aim was to investigate the involvement of NR2 subunits and Rac1, a member of Rho GTPase family, in retinal neuronal death. Glutamate-induced neuronal death in vitro was reduced after Rac1 inhibition and by NR2B blocking, but not NR2C/D subunits. Similar results were obtained in vivo after NMDA intravitreous injection, although active Rac1 was mainly detected in Müller glia processes, and it was inhibited by NR2B blockade. In addition, TNF-α level after NMDA injection were reduced by NR2B blocking and Rac1. Thus, our results suggest that excitotoxicity via NR2B/NMDA receptors activate Rac1 in Müller glia cells, which in turn controls the TNF-α production that triggers retinal ganglion cell death.
Pollard, Matthew. "Cloning and molecular characterisation of novel sodium dependent glutamine and glutamate transport systems." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364871.
Full textNamwindwa, Ernest Sinvula. "GABA and glutamate mimetics." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376436.
Full textRamos, Vicente David. "Phylogenetic Studies of Glutamate Receptors and their Auxiliary Subunits Update their Classifications and Uncover their Diverse Metazoan Evolutionary Histories." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/673959.
Full textEl glutamato es el principal neurotransmisor excitatorio del sistema nervioso de los vertebrados e invertebrados. Las proteínas involucradas en la neurotransmisión glutamatérgica, y especialmente los receptores de glutamato y sus subunitades auxiliares, juegan un papel clave en el funcionamiento del sistema nervioso. Así, entender su evolución y revelar su diversidad es esencial para comprender como ha evolucionado el sistema nervioso, dando forma a la función cognitiva. El análisis integral de la filogenia de estas proteínas en los metazoos ha revelado que su evolución es mucho más compleja de lo que se podia anticipar en base al genoma de los vertebrados. Esto es particularmente cierto para los receptores ionotrópicos de glutamato, pues su clasificación actual en seis clases (AMPA, Kainato, Delta, NMDA1, NMDA2 and NMDA3) estaría altamente incompleta. El trabajo aquí presentado propone una clasificación en 4 subfamilias que engloban 10 clases. Los receptores AMPA, Kainato y Delta de vertebrados pertenecerían a una de estas subfamilias, llamada AKDF, y las subunidades NMDA constituirían otra subfamilia. Además, también podrían existir dos subfamilias no descritas previamente, que son referidas como Epsilon y Lambda. Por otro lado, las familias de proteínas que contienen subunidades auxiliares de receptores AMPA (ARAS) han experimentado historias evolutivas menos complejas. No obstante, los vertebrados habrían reclutado para actuar como ARAS a la sinapsis proteínas de estas familias mediante procesos de neo y/o subfuncionalización que se dieron después de eventos de duplicación génica ocurridos en este linaje. Así este trabajo favorece la hipótesis de que la complejidad del sistema nervioso podría no haber evolucionado incrementando el conjunto de receptores de neurotransmisores en el genoma, sino augmentando la regulación de estos receptores en la sinapsis.
Glutamate is the major excitatory neurotransmitter in vertebrate and invertebrate nervous systems. Proteins involved in glutamatergic neurotransmission, and chiefly glutamate receptors and their auxiliary subunits, play key roles in nervous system function. Thus, understanding their evolution and uncovering their diversity is essential to comprehend how nervous systems evolved, shaping cognitive function. Comprehensive phylogenetic analysis of these proteins across metazoans have revealed that their evolution is much more complex than what can be anticipated from vertebrate genomes. This is particularly true for ionotropic glutamate receptors, as their current classification in six classes (AMPA, Kainate, Delta, NMDA1, NMDA2 and NMDA3) would be largely incomplete. New work proposes a classification into 4 subfamilies that encompass 10 classes. Vertebrate AMPA, Kainate and Delta receptors would belong to one of these subfamilies, named AKDF, and the NMDA subunits would constitute another subfamily. Furthermore, two previously unreported subfamilies would also exist, these are referred to as Epsilon and Lambda. On the other hand, protein families containing AMPA receptor auxiliary subunits (ARAS) have experienced less complex evolutionary histories. Nevertheless, vertebrates would have recruited to function as ARAS in the synapse proteins from these families by neo and/or subfunctionalization after gene duplication events occurred in this lineage. Thus, this work favours the hypothesis that nervous system complexity could have evolved not by increasing the set of neurotransmitter receptors in the genome, but by increasing the regulation of such receptors in the synapse.
Universitat Autònoma de Barcelona. Programa de Doctorat en Neurociències
Das, Sujan Chandra. "Glutamate Transporter 1 and Cystine-glutamate Anti-porter: Therapeutic Targets for Alcohol Dependence." University of Toledo Health Science Campus / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=mco1470161946.
Full textDean, Benjamin J. F. "The role of glutamate in rotator cuff tendinopathy : glutamate in rotator cuff tendinopathy." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:8f590630-b52f-4b32-a1c1-9914dbd694f3.
Full textFickinger, Andira Michele da Cruz. "Papel dos receptores de glutamato tipo NMDA em macrófagos, células dendríticas e células T CD4 ativadas in vitro." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/42/42133/tde-11072014-091556/.
Full textNeuroimmunology is a field within immunology which studies the relationship between the nervous system and the immune system. Several studies have demonstrated the direct ability of neurotransmitters in modulating the immune response, as for cytokines in influencing cognitive functions. In this context, glutamate stands out for being the most important and abundant neurotransmitter in the mammal central nervous system. Its role is exerted through two main types of receptor: i) ionotropic receptors (iGluR) and ii) metabotropic receptors (mGluR). The discovery of glutamate receptor expression in immune cells has led to scientific interest, raising issues concerning its expression and function. In the present study, we evaluated parameters such as cell viability, lymphoproliferation, and activation of the MAP quinase pathway by the NMDA receptor on total splenocytes and lymphocytes cultured in vitro. Our results demonstrate that naive and activated lymphocytes present different profiles of NMDA receptor expression. The use of MK801, an antagonist for this receptor, was able to reduce the T CD4 and T CD8 lymphocyte proliferation stimulated with anti-CD3 in splenocyte culture. Such reduction may be explained by the increase of the cellular death rate, evaluated by annexin-V staining, indicator of apoptosis or 7-AAD, indicator of necrosis. With the intent of understanding part of the NMDA receptor signaling in the immune system, we evaluated the ERK 1,2 MAP quinase phosphorylation in T CD4 lymphocytes activated in the presence of the agonist (NMDA) or the antagonist (MK801) of the receptor. We observed an increase in this quinase activation in the presence of NMDA, which is reversed by the MK801. When evaluating the role of the NMDA receptor in vivo, we verified a significant reduction in the degree of experimental auto-immune encephalomyelitis in animals treated with MK801. More interesting, this reduction also correlates to a reduction on the phosphorilation of ERK 1,2 in total splenocytes obtained at the seventh day post-immunization. In sum, our data suggest that the NMDA receptor has the role of activating important intracellular pathways, such as the MAP quinases ERK 1,2; and that its blockage results in cellular death in vitro. As so, this indicates the importance of glutamate as a modulator of the intensity of response and the viability of T CD4 e T CD8 lymphocytes in vitro e in vivo. Thus, our result contribute for a better understanding of the immunoregulation phenomena, especially those in the neuroimmunology ou neuroimmunomodulation field.
Christie, Andrew D. "The use of glutamate and dipeptides as substitutes for glutamine in animal cell cultures." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq23591.pdf.
Full textBrakspear, Karen. "Glutamate regulation for bone repair." Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/54184/.
Full textGrant, P. L. "The mechanism of glutamate decarboxylase." Thesis, Bucks New University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376413.
Full textLaketic-Ljubojevic, Ira. "Glutamate signalling in bone cells." Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311080.
Full textMcGrath, Catherine Jane. "Glutamate release mechanisms from megakaryocytes." Thesis, University of York, 2007. http://etheses.whiterose.ac.uk/9950/.
Full textAnneken, John H. "Glutamate and MDMA Neurobehavioral Toxicity." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1353342344.
Full textBrothers, Holly M. "Neuroinflammation, Glutamate Regulation and Memory." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1363603410.
Full textHartzoulakis, Basil. "Mechanistic studies on glutamate mutase." Thesis, University of St Andrews, 1994. http://hdl.handle.net/10023/14380.
Full textDanel-Brunaud, Véronique. "Glutamate et sclerose laterale amyotrophique." Lille 2, 1990. http://www.theses.fr/1990LIL2M084.
Full textMartins, Ana Caroline Vasconcelos. "Explicando Ab Initio a Intensidade de AtivaÃÃo e Antagonismo do Receptor GlutamatÃrgico GluR2." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8286.
Full textA transmissÃo de impulsos nervosos à feita por meio das sinapses, envolvendo neurotransmissores e receptores. Os receptores ionotrÃpicos glutamatÃrgicos (GluRs) sÃo importantes canais iÃnicos do sistema nervoso central, encontrados em sinapses de excitaÃÃo rÃpida, e estÃo relacionados a funÃÃes cerebrais importantes como aprendizado e memÃria. AlÃm disso, os GluRs tambÃm estÃo associados com certas doenÃas neurolÃgicas e psiquiÃtricas, como por exemplo: a doenÃa de Alzheimer, o mal de Parkinson, a epilepsia, o acidente vascular cerebral, a esclerose lateral amiotrÃfica e a esquizofrenia. Neste trabalho, tiramos vantagem dos dados disponÃveis na literatura da co-cristalizaÃÃo dos seguintes agonistas glutamato (C5H9NO4) e AMPA (C7H10N2O4), do agonista parcial cainato (C10H15NO4) e do antagonista DNQX (C8H2N4O6) com o receptor GluR2 com resoluÃÃo de 1,9 Ã, 1,7 Ã, 1,9 à e 1,8 Ã, respectivamente, para estudar a interaÃÃo destes quatro ligantes com a GluR2 por meio de mÃtodos computacionais ab initio. Os hidrogÃnios ausentes dos dados de difraÃÃo de raios-X foram colocados atravÃs de um processo semi-clÃssico de minimizaÃÃo da energia total GluR2-ligante. A seguir, as simulaÃÃes foram feitas usando a Teoria do Funcional da Densidade (DFT), tanto ao nÃvel da aproximaÃÃo da densidade local (LDA), como da aproximaÃÃo do gradiente generalizado (GGA), para descriÃÃo dos efeitos de troca e correlaÃÃo. A utilizaÃÃo do mÃtodo de fragmentaÃÃo molecular com capas conjugadas (MFCC) tornou possÃvel analisar a interaÃÃo dos ligantes com cada um dos resÃduos prÃximos e pÃs-prÃximos do GluR2. Considerou-se tambÃm a relevÃncia da blindagem dos resÃduos pÃs-prÃximos que interagem com os ligantes, bem como se fez uma anÃlise da energia de interaÃÃo dos resÃduos (prÃximos e pÃs-prÃximos) considerados com os Ãtomos dos ligantes (resultados apresentados nos grÃficos BIRD), sem e com mediaÃÃo das molÃculas de Ãgua existentes no sÃtio de ligaÃÃo (o que permite se determinar ab initio a relevÃncia da Ãgua na energÃtica da interaÃÃo ligante-GluR2). Obteve-se a energia total de interaÃÃo GluR2-ligante em funÃÃo da distÃncia dos centroides dos ligantes aos resÃduos, o que permitiu correlacionÃ-la à intensidade de ativaÃÃo e antagonismo dos neurotransmissores em questÃo. Demonstrou-se que ela segue a ordem AMPA > glutamato > cainato > DNQX somente quando um raio do sÃtio de ligaÃÃo suficientemente grande à considerado, o que explica dados experimentais publicados sobre a ativaÃÃo e antagonismo do receptor glutamatÃrgico GluR2, sugerindo que os resÃduos pÃs-prÃximos podem ser importantes para determinar o funcionamento do receptor. Para o glutamato, os resultados obtidos indicam que os resÃduos atrativos mais relevantes sÃo: Arg485, Lys730 (mediado pela Ãgua W39), Ser654, Leu650 mediado por W69, e Lys656 mediado por W22; os resÃduos repulsivos mais relevantes para o glutamato sÃo Glu402 (pÃs-prÃximo) mediado por W36, Glu657 e Asp651 (pÃs-prÃximos). Para o AMPA os resÃduos atrativos mais relevantes sÃo: Arg485, Thr655 mediado por W134, Lys730 mediado por W137, Lys656 mediado por W138, Lys449 e Arg684 (pÃs-prÃximos); os resÃduos repulsivos mais relevantes para o AMPA sÃo Glu402 mediado por W3, Asp651 mediado por W96 e W139 (pÃs-prÃximo), e Glu657 (pÃs-prÃximo) mediado por W140. Para o cainato os resÃduos atrativos mais relevantes sÃo Arg485, Ser654, Thr655 e Arg684 (pÃs-prÃximo); os resÃduos repulsivos mais relevantes para o Cainato sÃo Glu402, Glu657 mediado por W78 (pÃs-prÃximo) e Asp651. Para o DNQX os resÃduos atrativos mais relevantes sÃo Arg485, Glu705 e Tyr450 mediado por W26 e W137; o resÃduo repulsivo mais relevante para o DNQX à Leu498. Uma plÃiade de perspectivas relacionadas aos resultados obtidos reluz e dentre elas podemos destacar a possibilidade do desenvolvimento de agonistas e antagonistas glutamatÃrgicos com especificidades voltadas à diminuiÃÃo de efeitos colaterais quando utilizados no tratamento de doenÃas relacionadas à neurotransmissÃo glutamatÃrgica.
The transmission of nerve impulses occurs through the synapses, involving neurotransmitters and receptors. The ionotropic glutamate receptors GluRs are important ionic channels of the central nervous system, founded in rapid excitation synapses, and related to important cerebral functions like learning and memory. Besides this, GluRs are also associated with important neurological and psychiatric diseases like Alzheimer, Parkinson, epilepsy, cerebral ischemia, amyotrophic lateral sclerosis, and schizophrenia. In this work, we take advantage of the available data in the literature of co-crystallization of the following full agonists glutamate (C5H9NO4) and AMPA (C7H10N2O4), the partial agonist kainate (C10H15NO4) and the antagonist DNQX (C8H2N4O6) with the GluR2 receptor with resolution of 1.9 Ã, 1.7 Ã, 1.9 Ã and 1.8 Ã, respectively to study the interaction of these four ligands with GluR2 by means of ab initio computational methods. The absent hydrogens in the GluR2-ligand X-ray diffraction data were inserted through a semi-classical total energy minimization process. Next, the simulations were performed within the scope of the Density Functional Theory (DFT), both in the local density approximation (LDA) as generalized gradient approximation (GGA) for the description of exchange-correlation effects. The use of the molecular fragmentation method with conjugated caps (MFCC) allowed to analyze the interaction between the ligands with each one close and next-closed GluR2 residues. It was also considered the relevance of the screening of the next-closed residues with interact with the ligands, and it was performed an analysis of the interaction energy between the focused residues (close and next-closed) with the atoms of the ligands (results depicted in the BIRD panels), without and with the mediation of water molecules existing in the binding pocket (which allows to determine ab initio the relevance of water in the GluR2-ligands energetic). It was obtained the GluR2-ligand total energy interaction as a function of the distance between the ligand centroid and the residues, which allowed to correlate it to the activation strength and antagonism of the ligands focused. It was demonstrated that it follows the order AMPA > glutamate > kainite > DNQX only when a large enough binding pocket radius is taken into account, explaining the experimental data published on the activation and antagonism of the glutamatergic receptor GluR2 and suggesting the next-closed residues can be important to determine the receptor functioning. For the glutamate, the obtained results point that the most important attractive residues are Arg485, Lys730 (water W39 mediated), Ser654, Leu650 (water W69 mediated), and Lys656 (water W22 mediated); the most important repulsive residues for the glutamate are Glu402 (next-closed water W36 mediated), Glu657 and Asp651 (nex-closed). For AMPA, the most important attractive residues are Arg485, Thr655 (water W134 mediated), Lys730 (water W137 mediated), Lys656 (water W138 mediated), Lys449 and Arg684 (next-closed); the most important repulsive residues for AMPA are Glu402 (water W3 mediated), Asp651 (next-closed, water W96 and W139 mediated), and Glu657 (next-closed, water W140 mediated). For kainate the most important attractive residues are Arg485, Ser654, Thr655 and Arg684 (next-closed); the most important repulsive residues for kainite are Glu402, Glu657 (next-closed, water W78 mediated) and Asp651. For DNQX, the most important attractive residues are Arg485, Glu705 and Tyr450 (water W26 and W137 mediated); the most important repulsive residue for DNQX is Leu498. A pleiade of perspectives related with the obtained results shines, among which one can highlight the possibility to develop glutamatergic agonists and antagonists with specificities related to decrease side effects when used in the treatment of maladies related with the glutamatergic neurotransmission.
Grinberg, Ilana Elman. "Caracterização de crianças portadoras de câncer segundo sensibilidade ao umami e consumo alimentar." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/6/6138/tde-05042011-092036/.
Full textIntroduction: The Acute Lymphoblastic Leukemia (ALL) and non-Hodgkin Lymphoma (NHL) are the most frequent cancers in children and food intake can be reduced by chemotherapy. The sense of taste is a result of the detection and response to the sweet, salty, sour, bitter and umami stimulus. The latter is identified by monosodium glutamate (MSG) and is related to the increase of palatability, which may contribute to improve food acceptance in children with cancer. Objective: identification of the thresholds of detection of umami taste and food quality in children with LLA and LNH. Methodology: the threshold sensitivity test was applied in order to determine the threshold of the umami taste using six increasing concentrations of deionized water and MSG. A 24-hour recall and food frequency questionnaire were applied to check food intake. Weight and height were measured and the BMI was used to determine the nutritional status, according to the National Center of Health Statistics (2000). The sample was characterized by the distribution of the frequency of the variables, with the help of the Epinfo Version 6.0 statistical package. The statistical and graphical analyses were done using the R statistical software, version 2.6.2. The Cluster test was applied to characterize the sample. Results: from the 102 patients, 94 were sensitive to umami taste. 54,3 per cent were male and 45,7 per cent were female. 78,4 per cent had ALL and 21,6 per cent had NHL. 91 per cent were in the maintenance stage. Regarding age, 38,3 per cent were between 6 and 7 years old; 20,6 per cent were between 8 and 9 years old; 15,7 per cent were between 10 and 11 years old; 15,7 per cent were between 12 and 13 years old and 9,8 per cent were 14 years old. 8,5 per cent were underweight, 66 per cent were eutrophic and 25,5 per cent were overweight or had obesity. The most consumed product was instant noodles, rich in monosodium glutamate. The tabasco and soy sauces were the least consumed. The favorite food was snacks and instant noodles and mustard was the food they liked the least. There was no statistically significant difference between the thresholds of sensitivity to umami and the variables in study. The gathering of the sample characterized four groups: Group 1 formed by younger children, most male and eutrophic, more sensitive to the umami taste; Group 2 formed by most eutrophic and female children, showing lower intake of carbohydrates and higher intake of proteins and lipids; Group 3 formed by older children, most eutrophic and male, showing higher caloric and carbohydrate intake; Group 4 formed by eutrophic and overweight children, most male and with lower caloric intake, less sensitive to the umami taste. Conclusion: children are sensitive to the umami taste and this characteristic does not depend on the sex, age, nutritional status, treatment stage, caloric and macronutrients intake. The food quality and age were determinant variables of the similarities among the groups. The test of sensitivity for the detection of the umami taste is of great interest in the knowledge of food intake behavior and in the increase of food acceptance
Leleu, Olivier. "Étude du métabolisme azoté du colza : régulation de l'activité nitrate réductase en fonction du développement et des sources azotées." Lille 1, 2000. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2000/50376-2000-306.pdf.
Full textVieira, Lisvane Paes. "Caracterização molecular e bioquímica da prolina desidrogenase de Trypanosoma cruzi, um possível alvo terapêutico." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/42/42135/tde-09122010-102717/.
Full textIn the present work, we demonstrated the proline dehydrogenase enzymatic activity (PRODH) for the protein encoded by a gene annotated as a proline oxidase in the T. cruzi genome data base. This activity was shown firstly through complementation of a S. cerevisiae lineage lacking its endogenous PRODH gene. The PRODH gene was also expressed in a bacterial system and the active recombinant protein was obtained. Experiments performed with both, complemented yeasts and T. cruzi epimastigotes, showed a correlation between the intracellular free proline levels and the oxidative stress resistance. Quantitative RT-PCR assay revealed that the PRODH gene is differentially expressed across T. cruzi life cycle, being the highest expression level shown by the intracellular epimastigote form, this result was confirmed by Western blotting. Both results are in accordance with the fact that proline is essential for the differentiation of the intracellular epimastigote into trypomastigote. Subcellular localization assays showed that PRODH is present preferentially in the mitochondria. In silico analyses of the PRODH peptidic sequence indicated the presence of an EF-hand domain, wich is, usually, involved in Ca2+ binding. In fact, our results confirm not only the ability of such domain of binding Ca2+ but also its function in the activity regulation. Mitochondrial respiration assays using proline as substrate showed that PRODH transfers electrons and generates FADH2, with an eficience comparable to that of the complex II (Succinate dehydrogenase). Experiments using the T4C, an analogue of proline that inhibits the proline uptake, caused the depletion of the intracellular free proline, which was followed by the significantly decrement of the cellular viability of the parasites under nutritional and oxidative stresses. Taken together, this data suggest that proline transporters are promising drug targets when combined with other drugs that act by generating reactive oxygen species.
Visa, Bombardo Joan. "Potenciació de l’aprenentatge i la memòria amb agonistes del glutamat en models animals de dèficits cognitius." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/668068.
Full textThe progressive aging of the population may involve a high incidence of neurodegenerative diseases, which is an important social problem that requires research. The cerebral regions especially sensitive to the effects of aging are the prefrontal cortex (PFC) and the hippocampus (HPC), with special involvement of its receptors N-methyl-D-aspartate (NMDAr) and α-amino-3-hydroxy-5-methyl-4-isoxazolpropionic (AMPARr). Given the involvement of these glutamatergic receptors in the cognitive processes, several studies have used them as targets for treatments aimed at cognitive improvement. Therefore, we believe that the administration of glutamatergic agonists could reverse cognitive deficits associated with aging, or induced by drugs. In the present thesis we have studied in rats the intracerebral administration in the prelimbic cortex (CPL), on the one hand, of the ampakine S18986 to reduce the memory deficits produced by: a) cholinergic hypofunction due to the administration of scopolamine (SCOP) into the CPL (Experiment 1) and b) inactivation of the parafascicular nucleus of the thalamus (PFn) by muscimol (GABAergic agonist) (Experiment 2). The effects of these treatments have been evaluated in behavioural paradigms of implicit memory (Odour Discrimination Task, ODT) and relational memory (Social Transmission of Food Preference, STPF). On the other hand, we have studied the capacity of the treatment with d-cycloserine (DCS), a partial agonist of the NMDAr, to enhance working memory (WM) and cognitive flexibility in aged rats, two cognitive functions clearly depleted during the aging process. The effects of intracerebral administration of DCS in the CPL on these functions and on short- and long-term memory have been evaluated using the paradigms of Delayed Matching / Non-Matching to Position (DMTP / DNMTP), in a Y-maze and in an operant alternate response task (Experiment 3). The results of experiments 1 and 2 indicate that SCOP into the CPL produces a memory-blocking effect on the DSO in the 24-h recall test and the PFn inactivation prevents the acquisition of this associative olfactory task. The cholinergic hypofunction and the alteration of the thalamic influence on the PFC could explain these results. Moreover, S18986 reduced the number of errors committed in the DSO acquisition, respect to the control group and the group treated with SCOP. However, these facilitating effects are not observed, neither in the retention sessions nor in other behavioural models such as the TSPA. Different methodological aspects, such as the administered doses or the dilution medium of the drug, could explain the divergences observed with respect to other experiments. The most remarkable procognitive effects have been observed in the Experiment 3, where the intracerebral administration of DCS has reversed the WM alterations associated with natural aging. The pre-training administration of DCS to the CPL has matched the performance of the treated old rats to the young rats. These results agree with other studies showing that the beneficial effect of DCS seems to be associated with the existence of some kind of cognitive deficit. In general, the effect of DCS has been more evident in WM (DMTP) than in cognitive flexibility (DNMTP) or in short-term memory (Y-maze). These divergences could be a consequence of a sensitization effect of the receptors due to the chronic administration of the treatment or the temporal administrationwindow. On the other hand, in the 7-d memory test of the alternate response task, the DCS treatment in aged animals facilitated itsperformance, equalling it to the young animals. The administration of the different treatments applied in this thesis did not have any significant effect in other variables that could have influenced the results, such as the olfactory capacity, the motor activity or the motivation to eat. With the results obtained in this thesis we provide knowledge about potential treatments aimed at glutamatergic modulation to reverse cognitive deficits resulting from aging, or other pathologies associated with brain dysfunction. Both the administration of S18986 and the DCS promote mechanisms of synaptic plasticity, such as long-term potentiation, which facilitate long-term memory and also short-term memory, providing facilitation of tasks with a relevant attentional component. Additionally, the fact that the use of partial agonists reduces the possibility of toxicity and that these drugs promote neuroprotective mechanisms, turns these two drugs into potential nootropic substances, which could be used as treatment of cognitive deficits, taking into account that additional research is required on the possible dose-dependent effects, the agonist profile and other issues.
Oldenziel, Weite Hendrik. "Application of a glutamate microsensor to brain tissue construction, evaluation and application of a glutamate microsensor /." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2006. http://irs.ub.rug.nl/ppn/297660691.
Full textGuillaume, Anaïs. "Vers des analogues gamma, gamma-disubstitués du glutamate comme ligands potentiels des récepteurs métabotropiques du glutamate." Paris 11, 2010. http://www.theses.fr/2010PA114851.
Full textMetabotropic glutamate receptors have received considerable attention over the past decade in view of their relevance in multiple aspects of glutamatergic transmission. The widespread expression of mGluRs through the central nervous system makes these receptors particularly attractives drug targets, and recent studies validate the therapeutic utility of mGluR ligands in neurological and psychiatric disorders such as Alzheimer’s disease, Parkinson’s disease, anxiety, depression and schizophrenia. It is in this context that we were interested in the synthesis of glutamic acid analogues. The first part of this thesis describes the construction of the glutamic acid’s framework. The synthetic approach involves the asymmetric Michael addition of chiral b-enaminoesters to a-substituted Michael acceptors. In the second part, two synthetic pathways to the four diastereomers of our analogues are described. In this approach, the intramolecular cyclization and then the opening of the cycle are the key-steps
Wehbe, Johny. "Analogues du glutamate et de l'aspartate : ligands des récepteurs métabotropiques et inhibiteurs du transport du glutamate." Montpellier 2, 2002. http://www.theses.fr/2002MON20088.
Full textGarside, Sarah. "Dopamine-glutamate interactions in the striatum." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq30137.pdf.
Full textRutten, Erica Petra Alberta. "Glutamate metabolism and supplementation in COPD." Maastricht : Maastricht : Universitaire Pers Maastricht ; University Library, Universiteit Maastricht [host], 2006. http://arno.unimaas.nl/show.cgi?fid=5333.
Full textYee, Chan Wai. "The targeting of metabotropic glutamate receptors." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393441.
Full textSoundarapandian, Mangala Meenakshi. "Glutamate Excitotoxicity in Epilepsy and Ischemia." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3169.
Full textPh.D.
Department of Biomolecular Science
Burnett College of Biomedical Sciences
Biomolecular Sciences PhD
Boycott, Hannah Elizabeth. "Hypoxic modulation of astrocyte glutamate transporters." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445941.
Full textMigueis, Antonio Miguel Borregana. "Structure function relationships in glutamate dehydrogenase." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247001.
Full textCallaghan, Josephine. "Studies on glutamate 1-semialdehyde aminotransferase." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297422.
Full textPilkington, Benjamin John. "Scaffolding group II metabotropic glutamate receptors." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415235.
Full textFry, V. A. H. "Microglial glutathione and glutamate : regulation mechanisms." Thesis, University College London (University of London), 2009. http://discovery.ucl.ac.uk/18703/.
Full textAshiuchi, Makoto. "STRUCTURE AND FUNCTION OF GLUTAMATE RACEMASE." Kyoto University, 1996. http://hdl.handle.net/2433/160867.
Full textKyoto University (京都大学)
0048
新制・論文博士
博士(農学)
乙第9225号
論農博第2056号
新制||農||722(附属図書館)
学位論文||H8||N2934(農学部図書室)
UT51-96-F462
(主査)教授 左右田 健次, 教授 加藤 暢夫, 教授 木村 光
学位規則第4条第2項該当
Karolewicz, Beata, L. Johnson, D. Maciag, T. Gilmore, Katalin Szebeni, Craig A. Stockmeier, and Gregory A. Ordway. "Glutamate Signaling Proteins in Major Depression." Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etsu-works/8622.
Full textPrice, Michelle B. "Functional Analysis of Plant Glutamate Receptors." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51946.
Full textPh. D.
Nolte, Scott. "Characterizing the Response of gdhA Transformed Tobacco to Glufosinate." OpenSIUC, 2009. https://opensiuc.lib.siu.edu/dissertations/94.
Full textRideau, Aline. "Dysfonction glutamatergique et GABAergique dans l'hippocampe après un stress immuno-inflammatoire prénatal chez le rat." Thesis, Montpellier 1, 2012. http://www.theses.fr/2012MON1T011.
Full textIntroduction: A late gestational exposure to lipopolysaccharide (LPS) leads to a behavioral and cognitive phenotype of neuropsychiatric disorders in male offspring. The main goal was to test the hypothesis of structural damage and imbalance between excitation and inhibition in the hippocampus. The secondary goal was to identify targeted therapeutic strategies.Methods: Pregnant rats were ip injected with either 500 μg/kg LPS from E.coli O55:B5 or 2 ml/kg saline vehicle on gestational day 19. Male offspring were studied at different developmental stages. The structural study was based on immunohistochemistry, the functional study on electrophysiological recordings of the activity of pyramidal cells in the CA1 area. The protective effect of N-acetylcysteine (NAC) given to pregnant rats after LPS injection was tested.Results: In male offspring, LPS induced late gestational immune challenge led to sustainable disarray of the pyramidal layer in the CA3 area, transient deficit of reelin expressing neurons, impaired long term depression of glutamatergic synapses (LTDe), due to NMDA receptor and GABAergic system dysfunction. An inhibitor of GABA reuptake completely restored plasticity lost after prenatal stress. NAC prevented cyto-architectural abnormalities.Conclusion: This thesis confirms the impact of a late prenatal immune challenge on hippocampal structure and function. It demonstrates that prenatal treatment with NAC and GABAergic tone modulation are valuable therapeutic strategies for the cognitive impairment associated with prenatal immune challenge
Mazuel, Leslie. "Spectroscopie RMN, des stratégies couramment utilisées en clinique vers les techniques de demain." Thesis, Clermont-Ferrand 1, 2014. http://www.theses.fr/2014CLF1MM12/document.
Full textParkinson's disease is a neurodegenerative disorder characterized by motor troubles such as akinesia, rigidity and tremor. The loss of dopaminergic neurons from the nigro-striatal pathway will lead to biochemical changes in the putamen. Especially, works on electrophysiology, micro dialysis and magnetic resonance spectroscopy (MRS) suggests hyperactivity of the glutamatergic cortico-striatal pathway associated with glial microenvironment changes. These observations suggest a modification of the glutamate-glutamine cycle occurring between neurons and astrocytes in response to neuronal loss.In this thesis, two approaches have been developed in order to follow by MRS the metabolic changes occuring in Parkinson's disease. In particular, we want to follow the changes in glutamate-glutamine cycle inside the putamen.in a first study, a a 1H MRS approach was used to assess the metabolic changes inside the putamen of Parkinson's disease without or under dopaminergic treatment. In this study, changes in N-acetylaspartate, creatine and myo-inositol were observed in Parkinsonian patients, but no change in glutamatergic metabolism was observed. This could be due to the lack of sensitivity of the technique to differentiate glutamate and glutamine pools.Thus, we chose to use a new 13C carbon MRS approach in order to follow dynamically in vivo the glutamate-glutamine cycle inside the brain: dynamic nuclear polarization (DNP). Thanks to the high sensitivity of this technique, it is now possible to follow metabolic pathways in vivo in real time. The implementation of DNP was assessed under a control group of animals. This technique offers a new promising tool for the analysis of this flow under pathologic conditions.To conclude, the MRS strategies for clinical diagnostic strategies remain, at present, poorly sensitive for the study of glutamate-glutamine cycle in vivo in humans. The development of DNP opens the door to a new approach for real-time monitoring of this cerebral metabolism Even if DNP is mainly used in preclinical studies at present, the development of new clinical systems could lead to its emergence as a new diagnostic strategy in clinical imaging
Souza, Helio Antonio Corrêa de. "Indicadores de lesão muscular e inflamação em ciclistas de elite em diferentes situações competitivas." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-30052008-130241/.
Full textThe objective of this research was to observe the effect of different road cycling competitions and a 20 days break period in Creatine Kinase (CK), Lactate Dehydrogenase (LDH), Interleukin-1(IL-1), Interleukin-6 (IL-6), Factor necrosis tumoral-alpha (TNF-a), prostaglandin E2 (PGE2) and in the ratio of Glutamine/Glutamate (Gln/Glu). The hypothesis tests were conducted with a sample of 12 professional cyclists which have completed 3 different road cycling races. The first and third ones (C1 and C3) were mass start races. The second one was a stage racing (C2). One analysis was made after a 20 days break period (C3). Blood samples were collected 24 hours before and 24 hours after each competition. There were no significant differences for none of the inflammatory mediators (p<0,05). Increases (p<0,05) were detected after the end of C2 and C3 for CK and LDH and low (p<0,05) in the ratio of Gln/Glu at C3. The conclusion of the research was that muscular damages are diagnostified in professional road cyclists 24 hours after the end of the stage racing and after mass start competition preceded by 20 days a break period.
Freitas, Thaís Fernanda Pinto de Almeida. "Imunodetecção do receptor metabotrópico mGluR8 no núcleo arqueado do hipotálamo de ratos Wistar e estudo dos efeitos, no receptor, resultantes da exposição oral sub-crônica ao glutamato monossódico." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256314.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Alimentar-se faz parte da cultura do ser humano nao estando unicamente associado a necessidades fisiologicas. Um alimento e constituido de diversas moleculas dentre elas os aminoacidos. O glutamato (GLU) e o anion de um dos principais aminoacidos encontrados nos alimentos que, alem de fazer parte da composicao dos alimentos, e uma molecula essencial para a fisiologia do ser humano. Pode tambem ser ingerido devido ao uso do aditivo alimentar glutamato monossodico (MSG). O GLU desempenha inumeras funcoes no organismo, dentre elas podemos citar: neurotransmissor excitatorio do sistema nervoso central, precursor de GABA e de aminoacidos como prolina e glutamina. Como neurotransmissor o GLU atua sobre quatro tipos de receptores: ionotropicos (AMPA, Kainato e NMDA) e metabotropicos (mGluR1-mGluR8) divididos em tres grupos de acordo com a sua homologia genetica e mecanismos de acao. Esses receptores estao presentes em praticamente todo o sistema nervoso central (SNC) e em outros orgaos como coracao, pulmao e intestino. O MSG e utilizado como realcador de sabor em todo o mundo, sendo que o descobrimento do gosto basico conferido pelo glutamato propiciou a producao industrial do seu sal, glutamato monossodico. O gosto basico conferido pelo glutamato e denominado de Umami, que traduzido do japones significa gosto bom, delicioso. Existem inumeros estudos sobre o uso do MSG como aditivo alimentar (funcao tecnologica), assim como sobre sua funcao fisiologica e seus efeitos no organismo de mamiferos. Organizacoes internacionais e agencias de regulamentacao de muitos paises tem reportado e/ou avaliado que o uso do MSG como aditivo alimentar e seguro. Todavia, alguns autores tem relatado efeitos adversos no sistema nervoso central (SNC) associados a exposicao ao MSG. Assim, o presente estudo teve como objetivo exibir dado morfologico sobre a localizacao do receptor mGluR8 no nucleo arqueado do hipotalamo (NARC) de ratos Wistar e avaliar o efeito da ingestao de dietas adicionadas de diferentes concentracoes de MSG (0% (controle), 1%, 2,5% e 5%) sobre o mGluR8. Tambem foi avaliado o ganho de peso corporeo entre os grupos de animais alimentados com as dietas adicionadas de diferentes concentracoes de MSG. Para evidenciar a presenca do receptor mGluR8 foi utilizada a tecnica de imunohistoquimica. Para avaliar o ganho de peso corporeo os animais foram pesados semanalmente. Todos os dados, tanto da contagem celular da tecnica de imunohistoquimica quanto da pesagem, foram analisados por analise de variancia. Os resultados obtidos indicam nao haver diferenca significativa (p <0,05) entre os ratos que ingeriram as dietas adicionadas das diferentes concentracoes de MSG, tanto para o ganho de peso corporeo como para a presenca de receptores mGluR8 no nucleo arqueado do hipotalamo (NARC)
Abstract: Food is part of human culture not only associated to physiological needs. Food is composed of several molecules among them amino acids. Glutamate (GLU) is the anion of one of the main amino acids found in foods that, besides being part of the food composition, is a molecule essential for human physiology. It can also be ingested due to the use of the food additive monosodium glutamate (MSG). The GLU performs many functions in the body, among them we could mention: excitatory neurotransmitter in the central nervous system, precursor of GABA and other amino acids such as proline and glutamine. As a neurotransmitter GLU acts on four types of receptors: ionotropic (AMPA, NMDA and kainate) and metabotropic (mGluR1-mGluR8) divided into three groups according to their genetic homology. These receptors are present in nearly all central nervous system (CNS) and other organs such as heart, lung and intestine. MSG is used as a flavor enhancer all over the world. The discovery of the basic taste due to glutamate, led to the industrial production of its salt, monosodium glutamate. The basic taste induced by glutamate is called Umami, which translated from Japanese, means good taste, delicious. There are numerous studies on the use of MSG as a food additive (technological function), as well as its physiological functions and its effects in the organism. International organizations and regulatory agencies of many countries have reported and / or evaluated that the use of MSG as a food additive is safe. However, some authors have reported adverse effects associated with exposure to MSG. Thus, this study aimed to assess the presences of the metabotropic receptor mGluR8 in the arcuate nucleus of the hypothalamus (ARH) of Wistar rats, and to evaluate the effects in the mGluR8 receptor resulting from the dietary intake of different concentrations of MSG (0% [control], 1%, 2 , 5% and 5%) during 90 days. Also, it was evaluated the body weight gain of the rats fed with the diets containing MSG in the different concentrations. To demonstrate the presence of the mGluR8 receptor immunohistochemistry technique was employed, and in order to elucidate the weight gain, the animals were weighed weekly. All the data, cell counts from the immunohistochemistry technique and from the rats weighing, were evaluated by analysis of variance. The results showed no significant difference (p<0.05) for both: body weight gain and the presence of mGluR8 receptors among the animals that were fed with the diets containing the different MSG levels
Mestrado
Engenharia de Alimentos
Mestre em Ciência de Alimentos