远距缺血后适应对缺血再灌注心肌的保护作用

Remote ischemia postconditioning protects against myocardial injury in rabbits

目的:探讨远距缺血后适应(RIP)对兔局部短期缺血再灌注心肌的保护作用。方法:将24只新西兰白兔随机平均分成4组:假手术对照组(S组)、缺血再灌注对照组(IR组)、缺血后适应组(Post组)、RIP组。采用TUNEL分析检测各组心肌组织的细胞凋亡情况,Western blot方法检测Bcl-2、Bax蛋白的表达。结果:RIP组心肌细胞凋亡指数[30.24±1.68)%]显著低于IR组[(53.30±12.88)%],P<0.01;Post组与RIP组心肌凋亡指数相比差异无统计学意义。Bcl-2基因的蛋白表达量RIP组高于IR组(0.97±0.16∶0.77±0.14,P<0.05);Bax基因的蛋白表达量RIP组低于IR组(0.76±0.18∶1.09±0.13,P<0.05)。Bcl-2、Bax基因的蛋白表达量在RIP组及Post组相比差异无统计学意义。结论:RIP显著减少了兔短期缺血再灌注诱导的心肌细胞凋亡程度与上调Bcl-2基因的蛋白表达,下调Bax基因的蛋白表达有关,与Post一样具有心肌保护作用。

Objective：To investigate the effects of remote ischemia postconditioning（RIP） on myocardial injury in rabbits.Method：Twenty-four rabbits were randomly allocated to four groups（n=6 for each group）,sham operation group（Group S）,ischemia/reperfusion group（Group IR）,ischemic postconditioning group（Group Post） and remote ischemia postconditioning（Group RIP）.Cardiomyocyte apoptosis were determined by in situ TDT-mediated dUTP nick end labeling（TUNEL） and DNA electrophoresis.The analysis of Bcl-2 and Bax proteins in apoptotic myocardiac cells were detected by western blot.Result：Compared with Group IR,AI was significantly reduced in Group RIP（P0.01）.Compared with Group S,Bcl-2 expression was higher in Group RIP than in Group IR,while Bax expression was lower in Group RIP than in Group IR.Conclusion：RIP can decrease the ratio of apoptosis and protect myocardial cells from IR injury by increasing Bcl-2 expression and decreasing Bax expression.