缺血后处理对犬肾缺血再灌注损伤氧化应激反应的影响

目的：探讨缺血后处理对犬急性肾缺血再灌注损伤氧化应激反应的影响.方法：将15只成年雄性杂种狗分为3组,每组5只,即假手术组（S组）、缺血再灌注组（I/R组）、缺血后处理组（IPO组）.在肾缺血60min后立即给予再灌注30 s,再缺血30 s,循环3次,然后完全恢复灌注.术前及术后每天检测血清肌酐（Cr）浓度,检测肾组织超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量、过氧化氢酶（CAT）、总抗氧化能力（TAC）.术后犬存活3天,杀死后取左肾标本,光镜下观察肾组织病理学改变.结果：IPO组与I/R组术后3天连续比较,血清Cr浓度有显着降低,差异有统计学意义（P〈0.05）;IPO组与I/R组比较,SOD、CAT、TAC活性升高,MDA浓度降低,病理损伤明显减轻,差异有统计学意义（P〈0.05）.结论：缺血后处理能减轻肾缺血再灌注损伤氧化应激反应,其机制与氧自由基清除有关.

Effects of Oxidative Stress in Renal Ischemia-Reperfusion Injury by Ischemic Postconditioning in Dogs

Objective：To investigate the effects of oxidative stress in the acute renal ischemia/ reperfusion （I/ R）injury by ischemic postconditioning （IPO） in dogs. Methods： 15 adult male mongrel dogs were randomly divided into 3 groups with 5 animals in each group：group sham operation（S） ;group ischemia/reperfusion（I/R） ;group ischemic postconditioning（IPO） were subjected to 3 episodes of 30s reperfusion followed by 30s ischemia immediately after 60 rain renal ischernia before reperfusion completely. Blood samples were obtained for determination of blood creatinine（Cr） concentrations before operationand and every days alter operation. The dogs were killed in the third day after operation and left kidneys were removed for determination of superoxide dismutase（SOD） activities, catalase（CAT） activities, malondialdehyde（MDA） contentrations and total anti-oxidant capacity （TAC）. The changes of renal tissue were detected by microscope. Results： Blood Cr concentrations of group IPO were significantly decreased by compared constantly with group I/R in 3 days after operation. SOD activity,CAT activities and TAC were significantly increased and MDA concentrations were significantly decreased in group IPO as compared with group I/R （P〈0.05）. Microscopic examination showed that the renal I/R injury was significantly attenuated by ischemie postconditioning. Conclusions：Ischemic post-conditioning can attenuate oxidative stress induced by I/R by scavenging of oxygen free redicals and the mechanism has a relationship with the oxygen scavenging.