Role of mitochondrial KATP channel in reduction of renal ischemia- reperfusion injury by ischemic postconditioning in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the role of mitochondrial KATP (mito-KATP) channel in reduction of renal ischemia-repeerfusion (I/R) injury by ischemic postconditioning (IPo) in rats. Methods Thirty-five adult male SD rats weighing 250-280 g were randomly divided into 5 groups ( n = 7 each) group Ⅰ sham operation (group S); group Ⅱ I/R; group Ⅲ IPo; group Ⅳ 5-HD + I/R and group V 5-HD + IPo. The rats were anesthetized with intraperitoneal (IP) chloral hydrate 300 mg/kg. Bilateral kidneys were exposed and their pedicles were occluded for 45 min with atraumatic mini-clamp followed by 6 h reperfusion in group Ⅱ - Ⅴ . In group Ⅲ and Ⅴ 3 cycles of 10 s reperfusion followed by 10 s ischemia were applied immediately after 45 min kidney ischemia. In group Ⅳ and Ⅴ 5-HD (a specific blocker of the mito-KATP channel) 10 mg/kg was given IP at 30 min before ischemia. Blood samples were obtained at 6 h of reperfusion for determination of serum creatinine (Cr) and urea nitrogen (BUN) concentrations. The animals were then killed. Bilateral kidneys were removed for determination of mitochondrial membrane potential in the renal tubular epidural cell and intracellular reactive oxygen species (ROS)content and free Ca2+ concentrations. Results Renal I/R significantly increased serum Cr and BUN concentrations and intracellular free Ca2+ concentration and ROC content and decreased mitochondrial membrane potential as compared with sham operation group. IPo significantly attenuated the I/R-induced changes mentioned above. The protective effects of IPo against renal I/R injury was reversed by 5-HD. Conclusion Mito-KATP channel is involved in reduction of I/R-induced renal injury by ischemic postconditioning.