Efeito do pré-condicionamento isquêmico à distância na ototoxicidade em ratos induzida por cisplatina

• Ano de defesa: 2015
• Autor(a) principal: Martins, Marcos Jullian Barreto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Audição; Perda Auditiva; Cisplatino
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/15362

Ototoxicity can be decribed as a lost of auditory or vestibular function as a consequence of injury in cells of the inner ear. Despite of this effect, same antineoplastic drugs, as cisplatin, can not be excluded as an option for the pacient with a malignant tumor, because of its efficiency and the lack of options for terapeutic protocols. Remote ischemic preconditioning (RIPC) was proposed from the study that the ischemic preconditioning (IPC) of a cardiac vascular area could protect another completely different. Among the studies with RIPC, studies on the induction of ischemia in animals by ischemia and reperfusion of anterior or posterior paws is widely used, due to its easy application and low cost. Based on these knowledge, a study was proposed with induction by cisplatin ototoxicity in rats at a dose of 32mg / kg, divided in 04 applications of 08 mg / kg / day, which proved to be a toxic dose and low mortality from the experience of our research group, and otoprotection with ischemic preconditioning in the right hind paw. The Wistar rats were anesthetized. Those with normal otoscopy were evaluated by hearing tests through auditory brainstem response (ABR). After this evaluation, cisplatin was administered intraperitoneally, group 1 (n=08 rats), and saline intraperitoneally, group 2 (n=08 rats). In groups 3 (n=09 rats) and 4 (n=07 rats), there was a right hind paw ischemia for 10 min followed by reperfusion for 30 minutes, when it was administered after intraperitoneal cisplatin (group 3) and saline (group 4). At the end (D4), all were evaluated by ABR. The right temporal bone was removed after euthanasia. The cochlea was dissected for the techniques of optical microscopy and immunohistochemistry. Based on the results of this study, it was found that the RIPC, a mechanism already largely established, protects significantly the functional damage in the cochlea by cisplatin, through functional evaluation ABR (p = 0.0477). There was no statistical difference in the analysis by optical microscopy (p> 0.05). Reversal immunostaining was observed in group 3, tumor necrosis factor α and nitric oxide synthase induced lesion stria vascularis of cisplatin. It was obtained protection of the sisthemic toxicity of cisplatin. This study found that the RIPC protected the cisplatin-induced ototoxicity in functional assessment by ABR and protected systemic toxicity by the evaluation of weight measures.