An?lise dos efeitos do trans-resveratrol sobre a nocicep??o espont?nea induzida pela capsaicina e glutamato em camundongos

• Main Author: Bazzo, Karen Olivia
• Other Authors: Campos, Maria Martha
• Format: Others
• Language: Portuguese
• Published: Pontif?cia Universidade Cat?lica do Rio Grande do Sul 2015
• Subjects: MEDICINA; FARMACOLOGIA; ANIMAIS - EXPERI?NCIAS; DOR - CONTROLE; CNPQ::CIENCIAS DA SAUDE::MEDICINA
• Online Access: http://tede2.pucrs.br/tede2/handle/tede/1654

Made available in DSpace on 2015-04-14T13:35:21Z (GMT). No. of bitstreams: 1 436229.pdf: 1123384 bytes, checksum: 85ba9f774662974dca27a3df7d39708d (MD5) Previous issue date: 2012-01-16 === Resveratrol (RSV) is a polyphenol with well-characterized anti-inflammatory and antioxidant actions, with some evidence for antinociceptive effects. Herein, we have evaluated the effects of RSV in two acute mouse models of spontaneous nociception, induced by capsaicin and glutamate, with some attempts to define the possible mechanisms of action of this compound. The oral administration of RSV (100 mg/kg) significantly reduced the licking behavior elicited by the intraplantar injection of capsaicin (1.6 μg/paw) or glutamate (10 μmol/paw). The co-administration of RSV, into the mouse paw (25 μg/site), markedly prevented glutamate-induced licking, without affecting capsaicin-elicited responses. Otherwise, the i.t. injection of RSV (300 and 600 μg/site) widely reduced the licking behavior caused by capsaicin, but not by glutamate.Lastly, the i.c.v. injection of RSV (300 μg/site) caused only a mild inhibition of capsaicin-induced nociception, whereas glutamate responses remained unaffected. Unexpectedly, the co-administration of RSV (300 μg/site) was able to inhibit the biting behavior induced by i.t. injection of glutamate (30 μg/site), leaving capsaicin (6.4 μg/site)-induced biting unaltered. Of note, the oral treatment with RSV (100 mg/kg) resulted in a significant inhibition of capsaicin-induced increase of both c-Fos and COX-2 immunolabeling in the lumbar spinal cord, as well as the COX-2 expression in cortex. In glutamate model, the oral administration of RSV failed to affect either c-Fos or COX-2 activation in spinal or brain tissues. Data provides new evidence showing that analgesic effects of RSV are mediated by different mechanisms of action and anatomical sites, depending on the algogenic stimulus. === O resveratrol (RSV) ? um polifenol natural com efeitos anti-inflamat?rios e antioxidantes bem descritos. Efeitos significantes sobre a hiperalgesia inflamat?ria induzida por carragenina em ratos j? foram demonstrados. Neste estudo, foram avaliados os efeitos da administra??o de RSV em dois modelos de nocicep??o espont?nea, induzida por capsaicina e glutamato em camundongos, com abordagens para defini??o dos poss?veis mecanismos de a??o deste composto. A administra??o oral de RSV (100 mg/kg) reduziu significativamente o efeito comportamental provocado pela inje??o intraplantar de capsaicina (1,6 μg/pata) ou glutamato (10 μmol/pata). A co-administra??o de RSV intraplantar (25 μg/s?tio) preveniu a nocicep??o aguda induzida por glutamato, sem afetar o comportamento induzido pela capsaicina. Em contraste, a inje??o intratecal de RSV (300 e 600 μg/s?tio) reduziu a nocicep??o causada pela capsaicina, mas n?o pelo glutamato.A administra??o intracerebroventricular de RSV (300 μg/s?tio) inibiu parcialmente a nocicep??o induzida pela capsaicina, enquanto que a resposta induzida pelo glutamato permaneceu inalterada. A co-administra??o de RSV (300 μg/s?tio) foi capaz de inibir a nocicep??o induzida pela inje??o intratecal de glutamato (30 μg/site), n?o alterando o comportamento induzido pela capsaicina (6,4 μg/s?tio). O tratamento oral com RSV (100 mg/kg) resultou em uma inibi??o significativa da imunopositividade de c-Fos e de COX-2 na medula espinhal, causada pela capsaicina, bem como, a express?o da COX-2 no c?rtex . Em rela??o ao modelo de glutamato, a administra??o oral de RSV n?o afetou a express?o c-Fos ou COX-2 na medula espinhal ou c?rtex. Nossos dados fornecem novas evid?ncias demostrando que os efeitos analg?sicos do RSV s?o provavelmente mediados por diferentes mecanismos de a??o e s?tios anat?micos, dependendo do est?mulo algog?nico.