TRPA1 channels are sensors for noxious stimuli in a subset of nociceptive neurons. TRPA1 channels are also expressed in cells of the mammalian inner ear, but their function in this tissue remains unknown given that Trpa1–/– mice exhibit normal hearing, balance and sensory mechanotransduction. Here we show that non-sensory (supporting) cells of the hearing organ in the cochlea detect tissue damage via the activation of TRPA1 channels and subsequently modulate cochlear amplification through active cellshape changes. We found that cochlear supporting cells of wild type but not Trpa1–/– mice generate inward currents and robust long-lasting Ca2+ responses after stimulation with TRPA1 agonists. These Ca2+ responses often propagated between different types of supporting cells and were accompanied by prominent tissue displacements. The most prominent shape changes were observed in pillar cells which here we show possess Ca2+-dependent contractile machinery. Increased oxidative stress following acoustic overstimulation leads to the generation of lipid peroxidation byproducts such as 4-hydroxynonenal (4-HNE) that could directly activate TRPA1. Therefore, we exposed mice to mild noise and found a longer-lasting inhibition of cochlear amplification in wild type than in Trpa1–/– mice. Our results suggest that TRPA1-dependent changes in pillar cell shape can alter the tissue geometry and affect cochlear amplification. We believe this novel mechanism of cochlear regulation may protect or fine-tune the organ of Corti after noise exposure or other cochlear injuries.

TRPV4 is a non-selective cation channel with a wide expression and multiple cellular and systemic functions. Described initially as an osmosensor, it can also be activated by temperature and cell swelling. Due to this variety of activating stimuli it may have a promiscuous gating behavior which is mostly unknown. This Thesis research aims to get in-depth in the understanding of the molecular determinants of TRPV4 regulation. I provide evidences that the inositol trisphosphate receptor and its modulatory function on TRPV4 relies on its binding to the C-terminal tail of TRPV4. I discuss the role of the channels’ N-terminal tail in osmotransduction and show how a mutation that results in a channel with an impaired response to osmotic environments is associated to a pathophysiological condition such as hyponatremia. I also highlight the importance of this N-terminal tail and the binding to the regulatory protein PACSIN3 for the global conformation of the channel. / El TRPV4 és un canal catiònic no selectiu d’expressió generalitzada i funcions diverses. Tot i que inicialment es va descriure com un osmosensor sistèmic, avui sabem que també es pot activar per temperatura o per augments del volum cel•lular. Degut a la diversitat d’estímuls, el canal presenta diferents vies d’activació la major part de les quals són desconegudes. Aquesta Tesi pretén estudiar en detall els mecanismes moleculars que regulen l’activitat del canal. Aportem evidències del lloc d’unió a la cua C-terminal del receptor d’inositol trifosfat així com la seva modulació sobre l’activitat del TRPV4. També discutim el rol de la cua N-terminal en la osmotransducció i presentem una mutació, generadora d’un canal amb una resposta anòmala a estímuls hipotònics, que està associada a una condició fisiopatològica com la hiponatremia. També destaquem la importància de la cua N-terminal i de la unió de la proteïna reguladora PACSIN3 en la conformació global del canal.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Sept. 16, 2008). Includes bibliographical references.

Orientador: Cláudia Herrera Tambeli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T19:36:40Z (GMT). No. of bitstreams: 1 Bonet_IvanJoseMagayewski_M.pdf: 8243433 bytes, checksum: a5cdaab90bdcc5bbba66a0e5e4a1293f (MD5) Previous issue date: 2013 / Resumo: O Receptor Potencial Transiente Ankiryn 1 (TRPA1) é um canal não seletivo a cátions importante na fixação do limiar nociceptivos e pertencente à superfamília de canais TRP. É expresso em fibra C-nociceptiva e células não neuronais envolvidas na liberação de mediadores pró-inflamatórios. No presente estudo, investigamos se o TRPA1 contribui para a hiperalgesia induzida pela carragenina em ratos, e se essa contribuição é mediada por mecanismos de inflamação, tais como liberação de citocinas pró-inflamatórias e migração de neutrófilos e/ou sensibilização direta do neurônio aferente primário. Avaliamos a sensibilização do nociceptor induzida pela carragenina utilizando estímulos mecânico (analgesímetro mecânico) e químico (capsaicina), com ou sem bloqueio farmacológico local do receptor TRPA1 pelo seu antagonista seletivo HC 030031. A carragenina induziu hiperalgesia com pico na terceira hora, persistindo até vigésima quarta hora. O bloqueio farmacológico do receptor TRPA1 por co-administração de HC 030031 diminuiu significativamente a hiperalgesia induzida pela carragenina na terceira hora e a pós-administração de HC 030031 (2hrs 55min) reduziu na terceira e na sexta hora. O silenciamento do gene do TRPA1, induzido por um pré-tratamento intratecal com Oligonucleotídeo antisense, preveniu a hiperalgesia induzida pela carragenina após 24 horas além de reduzir significativamente a expressão de TRPA1 em células dos gânglios da raiz dorsal (GRD) (L5-6). O tratamento com carragenina, por sua vez, não alterou a expressão do receptor TRPA1 no GRD, e tampouco afetou os níveis de citocinas e a migração de neutrófilos no tecido periférico (patas). Concluímos que TRPA1 tem papel importante no desenvolvimento e manutenção da hiperalgesia inflamatória induzida pela carragenina por contribuir diretamente na excitabilidade do nociceptor. Baseado nesses achados, sugerimos que o bloqueio de TRPA1 é uma estratégia promissora no desenvolvimento de futuras drogas para o controle e tratamento da dor / Abstract: The Transient Receptor Potential Ankiryn 1 (TRPA1) is a nonselective cation channel, important in setting nociceptive threshold belonging to the superfamily of TRP channels. It is expressed in nociceptive C-fibers and in non-neuronal cells involved in pro-inflammatory mediators release. In this study, we asked whether TRPA1 contributes to carrageenan-induced hyperalgesia in rats, and whether this contribution is mediated by mechanisms in inflammation, such as cytokine release and neutrophil migration and/or by a direct sensitization of the primary afferent nociceptors. We measured the carrageenan-induced nociceptive sensitization using a mechanical (mechanical analgesymeter) and a chemical (capsaicin) stimulus, with or without pharmacological blockade of TRPA1 by its selective antagonist HC 030031. Carrageenan-induced Hiperalgesia has peaked at the third hour and persisted until the twenty-fourth hour. Pharmacological blockade of TRPA1 receptor by co-administration of HC 030031 significantly lowered carrageenan-induced hiperalgesia at the third hour and post-administration (2hrs 55min) decreased at both third and sixth hours. The neuronal TRPA1 gene silencing induced by intrathecal pre-treatment with antisense oligodoexynucleotide completely prevented carrageenan-induced hyperalgesia over 24 hours and significantly reduced TRPA1 expression in the dorsal root ganglia cells (DRG ) (L5-6). However, carrageenan treatment, did not affect the TRPA1 expression on DRG, neither affected the cytokines levels and neutrophil migration in peripheral tissue (paws). We conclude that TRPA1 plays an important role in the development and maintenance of carrageenan-induced inflammatory hyperalgesia by directly contributing to nociceptor excitability. Based on these findings, we suggest that TRPA1 blockade is a promising strategy for the development of future drugs to pain treatment and control / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

This study explored the role of transient receptor potential melastatin 8 ion channels (TRPM8) in mechanisms of human glioblastoma (DBTRG) cell migration. Menthol stimulated influx of Ca2+, membrane current, and migration of DBTRG cells. Effects on Ca2+ and migration were enhanced by pre-treatment with hepatocyte growth factor/scatter factor (HGF/SF). Effects on Ca2+ also were greater in migrating cells compared with non-migrating cells. 2-Aminoethoxydiphenyl borate (2-APB) inhibited all menthol stimulations. RT-PCR and immunoblot analysis showed that DBTRG cells expressed both mRNA and protein for TRPM8 ion channels. Two proteins were evident: one (130-140 kDa) in a plasma membrane-enriched fraction, and a variant (95-100 kDa) in microsome- and plasma membrane-enriched fractions. Thus, TRPM8 plays a role in mechanisms that increase [Ca2+]i needed for DBTRG cell migration.

<p>In order to understand how the brain functions, under normal as well as pathological conditions, it is important to study the mechanisms underlying information integration. Depending on the nature of an input arriving at a synapse, different strategies may be used by the neuron to integrate and respond to the input. Naturally, if a short train of high-frequency synaptic input arrives, it may be beneficial for the neuron to be equipped with a fast mechanism that is highly sensitive to inputs on a short time scale. If, on the contrary, inputs arriving with low frequency are to be processed, it may be necessary for the neuron to possess slow mechanisms of integration. For example, in certain working memory tasks (e. g. delay-match-to-sample), sensory inputs may arrive separated by silent intervals in the range of seconds, and the subject should respond if the current input is identical to the preceeding input. It has been suggested that single neurons, due to intrinsic mechanisms outlasting the duration of input, may be able to perform such calculations. In this work, I have studied a mechanism thought to be particularly important in supporting the integration of low-frequency synaptic inputs. It is mediated by a cascade of events that starts with activation of group I metabotropic glutamate receptors (mGlu1/5), and ends with a membrane depolarization caused by a current that is mediated by canonical transient receptor potential (TRPC) ion channels. This current, denoted I_TRPC, is the focus of this thesis.</p><p>A specific objective of this thesis is to study the role of I_TRPC in the integration of synaptic inputs arriving at a low frequency, < 10 Hz. Our hypothesis is that, in contrast to the well-studied, rapidly decaying AMPA and NMDA currents, I_TRPC is well-suited for supporting temporal summation of such synaptic input. The reason for choosing this range of frequencies is that neurons often communicate with signals (spikes) around 8 Hz, as shown by single-unit recordings in behaving animals. This is true for several regions of the brain, including the entorhinal cortex (EC) which is known to play a key role in producing working memory function and enabling long-term memory formation in the hippocampus.</p><p>Although there is strong evidence suggesting that I_TRPC is important for neuronal communication, I have not encountered a systematic study of how this current contributes to synaptic integration. Since it is difficult to directly measure the electrical activity in dendritic branches using experimental techniques, I use computational modeling for this purpose. I implemented the components necessary for studying I_TRPC, including a detailed model of extrasynaptic glutamate concentration, mGlu1/5 dynamics and the TRPC channel itself. I tuned the model to replicate electrophysiological in vitro data from pyramidal neurons of the rodent EC, provided by our experimental collaborator. Since we were interested in the role of I_TRPC in temporal summation, a specific aim was to study how its decay time constant (τ_decay) is affected by synaptic stimulus parameters.</p><p>The hypothesis described above is supported by our simulation results, as we show that synaptic inputs arriving at frequencies as low as 3 - 4 Hz can be effectively summed. We also show that τ_decay increases with increasing stimulus duration and frequency, and that it is linearly dependent on the maximal glutamate concentration. Under some circumstances it was problematic to directly measure τ_decay, and we then used a pair-pulse paradigm to get an indirect estimate of τ_decay.</p><p>I am not aware of any computational model work taking into account the synaptically evoked I_TRPC current, prior to the current study, and believe that it is the first of its kind. We suggest that I_TRPC is important for slow synaptic integration, not only in the EC, but in several cortical and subcortical regions that contain mGlu1/5 and TRPC subunits, such as the prefrontal cortex. I will argue that this is further supported by studies using pharmacological blockers as well as studies on genetically modified animals.</p> / QC 20101005

Ca2+-activated potassium channels (KCa) and canonical transient receptor potential (TRPC) channels are essential to endothelial function. In ischemic heart disease, or in cardiac surgery, coronary endothelium is subjected to ischemia-reperfusion (I-R) / hypoxia-reoxygenation (H-R) injury. Hyperkalemic cardioplegic or organ preservation solutions used in cardiac surgery including heart transplantation also impair endothelial function. The present study was designed to mainly investigate whether endothelial dysfunction occurring in H-R or in hyperkalemic exposure is attributable to alterations of intermediate- and small-conductance KCa (IKCa and SKCa) channels, or TRPC channels, in particular, the TRPC3 channel. / Exposure to 60-min hypoxia followed by reoxygenation inhibited the vasorelaxant response of coronary arteries to IKCa / SKCa activator 1-EBIO. H-R reduced endothelial IKCa and SKCa currents and downregulated IKCa expression in PCECs. 1-EBIO enhanced endothelial K+ current that was blunted by H-R. / Exposure to hyperkalemic solutions decreased Ca2+ influx via TRPC3 in PCECs. The reduced Ca2+ influx in PCECs and the attenuated EDHF-mediated vasorelaxation in porcine coronary arteries, which were caused by hyperkalemic or cardioplegic / organ preservation solutions, were restored by OAG. / In PCECs, hypoxia for 60-min with reoxygenation reduced TRPC3 current and Ca2+ influx via TRPC3, which was accompanied by decreased NO release and endothelium-dependent vasorelaxation of porcine coronary arteries. The compromised endothelial function was restored by OAG. The translocation of TRPC3 to endothelial membrane was inhibited by H-R. / In TRPC3-overexpressing HEK293 cells, followed by reoxygenation, short-time hypoxia (10-min) enhanced, whereas prolonged hypoxia (60-min) reduced the current induced by TRPC3/6/7 activator OAG. / Our results indicate that: (1) Endothelial IKCa, SKCa and TRPC3 play an important role in regulating vascular tone; TRPC3 contributes to NO release from endothelial cells and is also involved in the function of EDHF. (2) H-R (60-30 min) reduces endothelial IKCa and SKCa currents with downregulation ofthe protein expression of IKCa. (3) H-R has dual effect on TRPC3 with short-time hypoxia (lO-min) enhancing whereas prolonged hypoxia (60-min) decreasing the electrophysiological activity of this channel. H-R (60-30 min) inhibits the translocation of TRPC3 to endothelial membrane. Furthermore, H-R inhibits Ca2+ influx via TRPC3 and such inhibition is associated with a decrease of NO production. (4) The activator of IKCa / SKCa or TRPC protects coronary endothelium against H-R injury. In coronary endothelium exposed to hyperkalemic or cardioplegic / organ preservation solutions, TRPC activator also exhibits protective effect. / The above findings are likely to have significant implications in ischemic heart disease and in modem cardiopulmonary surgery. / Whole-cell membrane currents of IKCa, SKCa, or TRPC3 were recorded by patch-clamp in primary cultured porcine coronary endothelial cells (PCECs). TRPC3 current was also studied in human embryonic kidney cells (HEK293 cells) transiently overexpressed with TRPC3 gene. Protein or mRNA expression of these channels was detected by Western blot or RT-PCR. Intracellular Ca2+ concentration was measured by Ca2+ imaging technique. Isometric force study was performed in a wire myograph and endothelial nitric oxide (NO) release was measured electrochemically by using a NO-specific microsensor in porcine coronary small arteries. / Huang, Junhao. / "December 2010." / Adviser: Qin Yang. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 138-165). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

A famÃlia de receptores de potencial transitÃrio (TRP) incluindo o receptor de potencial transitÃrio anquirina, subtipo 1 (TRPA1) tem mostrado ser um alvo terapÃutico potencial para o tratamento da dor aguda e crÃnica. Alguns estudos tÃm demonstrado que a resposta nociceptiva somÃtica se deve à ativaÃÃo dos receptores TRPA1 e sÃo efetivamente modulados atravÃs da ferramenta experimental, HC-030031, um antagonista seletivo. Contudo, existem poucos estudos que avaliam o papel dos receptores TRPA1 na dor visceral. Portanto, investigamos o papel do TRPA1 em modelos animais de nocicepÃÃo visceral induzido por diferentes substÃncias e tambÃm exploramos os possÃveis mecanismos envolvidos. Camundongos Swiss, machos (N=6) receberam carboximetilcelulose 0,5% (veÃculo CMC 0,5%, 1 mL/Kg, v.o.), HC-030031 (75, 150 ou 300 mg/Kg, v.o.), ou L-NAME (10 e 40 mg/Kg, s.c.) ou somente L-Arginina (600 mg/Kg, i.p.), 1 h apÃs foi administrado uma Ãnica injeÃÃo de IFO (400 mg/Kg, i.p.). A nocicepÃÃo visceral foi avaliada atravÃs do teste de Von Frey eletrÃnico previamente (T0) e 12 h (T1) apÃs a injeÃÃo de IFO com estimulaÃÃo abdominal atravÃs de um analgesÃmetro digital. Os resultados foram obtidos em gramas (T0-T1) pela variaÃÃo da hiperalgesia. Em seguida as bexigas dos animais foram removidas para pesagem, anÃlise e foram atribuÃdos escores macro e microscopicamente. Investigou-se, tambÃm, o efeito antinociceptivo visceral do HC-030031 atravÃs do modelo de nocicepÃÃo visceral induzido por Ãleo de mostarda (OM). Os animais foram tratados com CMC 0,5%, HC-030031 (18,75; 37,5 ou 75 mg/kg, v.o.) ou Morfina (5 mg/Kg, s.c.) isoladamente ou receberam Naloxona (2 mg/Kg, i.p.) previamente a estas drogas. Em seguida, OM 0,75% (50 &#956;L/colon) foi instilado localmente no cÃlon. A nocicepÃÃo visceral foi verificada atravÃs do teste de Von Frey previamente (T0) e 10 min. (T1) apÃs a injeÃÃo do OM. Em outro protocolo experimental, os animais foram tratados com CMC 0,5% (10 mL/kg, v.o.) ou HC-030031 (18,75; 37,5 ou 75 mg/Kg, v.o.) previamente a uma injeÃÃo intraperitoneal com Ãcido acÃtico 0,6% (AA, 10 mL/Kg,), zymosan (Zym, 1 mg/cavidade) ou misoprostol (MPT, 1 Âg/cavidade, um anÃlogo estÃvel de prostaglandinas). Imediatamente apÃs a injeÃÃo desses algogÃnicos, contabilizaram-se as contorÃÃes abdominais por 30 min. Adicionalmente, para investigar o papel de cÃlulas peritoneais residentes sobre o efeito do HC-030031, a cavidade peritoneal dos camundongos foi lavada com uma soluÃÃo de 30 mL (PBS + heparina) e os estÃmulos AA, Zym e MPT foram injetados i.p. Um grupo Sham foi incluÃdo tambÃm neste protocolo. Ao final do experimento, as contorÃÃes abominais foram registradas por 30 mim. Utilizou-se para a anÃlise estatÃstica, ANOVA/Student e Newman/Keul, foi considerado significativo um p < 0,05 (CEPA: Protocolo: 92/10). A IFO induziu significativa (p<0,05) nocicepÃÃo visceral (6,25Â1,08) e resposta inflamatÃria [escores edema 2(1-3); hemorragia 3(1-3) e peso bexiga (42,78 3,10)] comparado com o grupo salina (1,97Â0,89),[ 0(0-0); 0(0-0) e 20,01 0,7749] respectivamente. AlÃm disso, HC-030031(75 mg/Kg) e L-NAME (10 e 40 mg/Kg) preveniram de maneira significativa (p<0,05) da resposta nociceptiva (2,30Â1,07; 1,58Â0,86 e 0,2500  0,73) respectivamente quando comparado com o grupo IFO. O prÃ-tratamento com L-Arginina (6,844Â1,235) reverteu o efeito antinociceptivo do L-NAME 10 mg/Kg, (6,84Â1,23), mas foi ineficaz sobre o efeito do L-NAME 40 mg/Kg (1,500Â0,7361) e HC-030031 75 mg/Kg (0,7200Â0,6953). Contudo, o prÃ-tratamento com HC-030031 nÃo apresentou efeito antiinflamatÃrio. Adicionalmente, verificou-se que o OM induziu significativo (p<0,05) comportamento nociceptivo (6,333Â0,9458) quando comparado ao grupo salina (1,250Â0,9204). AlÃm disso, o HC-030031 preveniu de maneira significativa da resposta nociceptiva provocada pelo OM (1,536 Â0,7653). Avaliou-se tambÃm o envolvimento do sistema opiÃide no efeito antinociceptivo do HC-030031. Verificou-se que a morfina apresentou uma importante atividade antinociceptiva (0,07143Â0,07143) contra a nocicepÃÃo induzida por OM a qual foi significativamente revertida pelo prÃ-tratamento com naloxona (3,125 1,302). Por outro lado, o efeito antinociceptivo do HC-030031 nÃo foi afetado pela naloxona (2,240Â1,263). Adicionalmente, AA, Zym e MPT induziram respostas de contorÃÃes abdominais significativas (43,71Â4,43; 11,00Â2,11 e 9,00Â2.30, respectivamente) as quais foram significativamente inibidas com HC-030031 (18,75, 37,5 ou 75 mg/kg, v.o.) em todas as doses utilizadas no teste com AA (29,07%; 53,35% e 41,59%), no teste com Zym (55,85%; 61,03% e 71,20%) e no teste com MPT (63,88%; 83,33% e 88,88%). Uma vez que a prostaglandina ativa o nociceptor diretamente, demonstrou-se que o HC-030031 possivelmente inibe a nocicepÃÃo visceral atravÃs da estabilizaÃÃo direta de nociceptores. O efeito antinociceptivo do HC-030031 parece ser independente da inibiÃÃo de cÃlulas residentes inflamatÃrias, do Ãxido nÃtrico ou do sistema opiÃide. Este estudo fornece perspectivas para o manuseio da dor visceral atravÃs da modulaÃÃo dos canais TRPA1. / The description of the TRP family of receptors including TRPA1 has provided potential therapeutic targets for treating acute and chronic pain. Some studies have shown a somatic nociceptive response due to the TRPA1 receptors activation which is effectively modulated with the experimental tool, HC-030031, a TRPA1 antagonist. However, there are a few studies evaluating the role of TRPA1 receptors in visceral pain. Then aimed to investigate the role of TRPA1 in the animal models of visceral nociception induced by different substances and to explore the possible mechanisms involved. Swiss male mice (n=6) were given only Carboxymethyl cellulose (vehicle CMC 0.5%, 1 mL/kg, p.o.), the compound HC-030031 (75, 150 or 300 mg/Kg, p.o.) or L-NAME (10 or 40 mg/Kg, s.c.) alone or with L-arginine (600mg/Kg, i.p.) 1h previously a alone injection of IFO (400 mg/kg, i.p.). Visceral nociception was assessed through the von Frey test previously (T0) and 12h (T1) later IFO injection by the abdominal stimulation with a pressure meter. The results were obtained in grams (T0-T1). The bladder of these animals were also removed to weighted (BWW), analyzed and after given scores macro and microscopically. We also investigated the antinociceptive effect of HC-030031 in the model of mustard oil-induced visceral nociception. The animals were treated with CMC 0.5% or HC-030031 (18.75, 37,5 or 75 mg/kg) or Morphine (5 mg/Kg, s.c.) alone or with Naloxone (2 mg/Kg, i.p.) 1h previously the injection of Mustard oil (MO) 0,75% (MO, 50 ul/colon). Visceral nociception was assessed through the von Frey test previously (T0) and 10 min (T1) after MO injection by the abdominal stimulation with a pressure meter. The results were obtained in grams (T0-T1). In another experimental setting, the animals were treated with CMC 0.5% (1 mL/kg, p.o) or HC-030031 (18.75; 37.5 or 75mg/Kg, p.o.) previously an intraperitoneal injection with acetic acid 0.6% (AA, 10 mL/kg), zymosan (Zym, 1 mg/cavity) or misoprostol (MPT, a stable prostaglandin analogous, 1&#956;g/cavity) and immediately had the writhing responses counted for 30 min. In order to investigate the role of resident peritoneal cells on the effect of HC-030031, we washed the peritoneal cavity of mice with heparin added PBS (30 mL) and then AA, Zym or MPT were injected i.p. A Sham group was included. Eventually, the writhing responses were recorded. Statistical analysis was performed with ANOVA/Student Newman Keul as appropriate. p<0.05 was accepted. (CEPA: Protocol 92/10). IFO induced significant (p<0.05) visceral nociception (6.25Â1.08) and inflammatory response [scores to edema 2(1-3); hemorrhage 3(1-3); and bladder wet weight (42.78  3.1)] in comparison with saline treated group (1.97Â0.89), [0(0-0); 0(0-0); 20.01 0.7749] respectively. Moreover, HC-030031(75) and L-NAME (10 or 40 mg/Kg) prevented in a significant manner (p<0.05) the nociceptive response (2.30Â1.07; 1.58Â0.860 and 2500Â0.7361) respectively when compared with IFO-treated group. Although the pretreatment with L-arginine (6.844Â1.235) was able to reverse the antinoceceptive effect of L-NAME 10 mg/Kg, (6.84Â1.23), it failed to do the same (p>0.05) with L-NAME 40 mg/Kg (1.500Â0.7361) and HC-0300031 75 mg/Kg (0.72Â0.69). The same reversible effect of L-Arginine was observed for the anti-inflammatory activity of L-NAME (p<0.05). However, HC-030031 presented no anti-inflammatory effect. The antinociceptive activity of HC-030031 was also assessed in the MO nociception model. We verified that MO induced a significant (p<0.05) nociceptive behavior (6.333Â0.9458) when compared to saline injected mice (1.250Â0.9204). Moreover, HC-030031 prevented in a significant manner the nociceptive response elicited by MO (1.536Â0.7653). Furthermore, the involvement of opioid system in the antinociceptive effect of HC-030031 as tested. We observed that morphine presented an important antinociceptive activity (0.07143Â0.07143) against MO-induced nociception which was significantly reverted by naloxone pre-treatment (3.125 1.302). On the other hand, the antinociceptive effect of HC-030031 remained in spite the injection of naloxone (2.240Â1.263). In addition to that, AA, Zym and MPT induced significant writhing responses (43.71Â4.43; 11.00Â2.11; 9.00Â2.30; respectively) which was significantly inhibited with HC-030031(18.75, 37.5 e 75 mg/kg, p.o.) treated mice in all the doses tested (29.07%, 53.35% and 41.59%, in the AA test, 55.85%, 61.03% and 71.20%, in the Zym test, 63.88%, 83.33% and 88.88%, in the MPT induced nociception, respectively to 18.75, 37.5 and 75 mg/kg doses. Eventually, the reduction of cell population in the peritoneal cavity prevented the development of writhing responses in both AA and Zym injected mice, with no effect was visualized on MPT treated mice. We the conclude that, since prostaglandin activates the nociceptor directly, it was shown that HC-030031 inhibits visceral nociception possibly through the stabilization of the neuronal ends. The antinociceptive effect of HC-030031 seems to be independent of the inhibition of inflammatory resident cells, opioid and nitric oxide pathways. This study provides perspective for the effective management of visceral pain through the modulation of TRPA1 channels.

No description available.

TRPV channels play a role in both mammalian insulin signaling, with TRPV1 expression in pancreatic beta-cells, and in C. elegans insulin-like signaling through expression of OSM-9, OCR-1, and OCR-2 in stress response pathways. In response to a glucose-supplemented diet, C. elegans are know to have sensitivity to anoxic stress, exhibit chemotaxis attraction, and display reduced egg-laying rate. Transcriptome analysis reveals that glucose stimulates nervous system activity with increased transcript levels of genes regulating neurotransmitters. Ciliated sensory neurons are needed for a reduced egg-laying phenotype on a glucose-supplemented diet. Egg-laying rate is not affected when worms graze on glucose-supplemented Delta-PTS OP50 E. coli, which is defective in glucose uptake. This suggests a possible sensory neuron obstruction by exopolysaccharides produced by standard OP50 E. coli on glucose, eliciting a starvation response from the worm and causing reduced egg-laying rate. Glucose chemotaxis is affected in specific TRPV subunit allele mutants: ocr-2(vs29) and osm-9(yz6), serotonin receptor mutants: ser-1(ok345) and mod-1(ok103), and G-alpha protein mutant: gpa-10(pk362). TRPV deletion mutants had no effect on glucose chemotaxis, alluding to the modality role pf TRPV alleles in specific sensory neurons. The role of serotonin in a reduced egg-laying rate with glucose remains unclear.