Caracterização dos efeitos da exposição aos componentes do cigarro sobre o controle neural do sistema cardiovascular em ratos normotensos e ratos espontaneamente hipertensos

• Autor(a) principal: Valenti, Vitor Engrácia [UNIFESP]
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/9177
• topic: Fumaça; Barorreflexo; Poluentes do ar; Quarto ventrículo; Tabaco; Ratos Endogâmicos SHR; Animais; Air pollutants; Baroreflex; Fourth Ventricle; Smoke; Tobacco; Rats, Inbred SHR; Animals

Objectives: To evaluate the effects of sidestream cigarette smoke (SSCS) on neural control of cardiovascular system in normotensive and spontaneously hypertensive rats (SHR). Method: Wistar, Wistar-Kyoto rats (WKY) and SHR were exposed to SSCS for three weeks, five days per week, 180 minutes per day at a concentration of carbon monoxide between 100 and 300 ppm. Baroreflex was stimulated with a vasodepressor dose of sodium nitroprusside (NPNa, 50ìg/kg, iv) and with a pressor dose of phenylephrine (PE, 8ìg/kg, iv). In order to evaluate the effects of catalase inhibition into the fourth cerebral ventricle (4th V) on cardiovascular responses, we injected the catalase inhibitor 3-amino-1,2,4-triazole (ATZ, ìg/100ìL 0.01). Results: It was observed in Wistar rats exposed to SSCS that catalase inhibition caused more intense responses on basal HR and bradycardic peak. Central catalase inhibition affected in a higher intensity baseline HR and bradycardic peak WKY rats exposed to SSCS. On the other hand, in SHR SSCS exposure affected the tachycardic peak after central inhibition of catalase in a higher intensuty. Conclusion: Exposure to SSCS alters the sympathetic component of the baroreflex in WKY and SHR and caused more severe cardiovascular responses to catalase inhibition into the 4th V in Wistar and WKY rats.