RESUMO
BACKGROUND/PURPOSE: The aim of this study was to investigate the role of ischemic preconditioning (IPC) on ischemia/reperfusion (I/R)-induced injury of rat testis and determine the effects of 5-hydroxydecanoic acid (5-HD), a selective K(ATP) channel antagonist, and Y-27632, a selective Rho kinase inhibitor, on IPC. METHODS: I/R injury was induced by 180 min ischemia and 60 min reperfusion of testis. There were 5 groups. Group 1 served as untreated controls. The rats in Group 2 were subjected to I/R only. In Group 3, 3 cycles of IPC (5 min transient ischemia plus 5 min reperfusion) were performed prior to I/R. In groups 4 and 5, the rats were treated as in Group 3 but received intraperitoneal injections of 0.3 mg/kg Y-27632 or 10 mg/kg 5-HD prior to IPC, respectively. RESULTS: I/R led to severe histopathological lesions in the rat testis and significantly lowered the scoring. I/R resulted in significant elevation in tissue lipid peroxide levels, myeloperoxidase (MPO) activity, and total antioxidative capacity (TAC), total oxidative status, and oxidative stress index levels. Protective effects of IPC on I/R-induced testicular injury of rats were observed with the significant recovery in these biochemical parameters. Y-27632 treatment led to a significant decrease in MPO activity, but there were no significant changes in the remaining parameters. Effects of IPC were blocked by 5-HD except in the TAC levels. CONCLUSION: Our results showed that IPC protected rat testis against I/R-induced injury via activation of KATP channels. Additionally, Rho kinase inhibition preserved the effects of IPC in testis.
