球囊垫扎法实施缺血后适应对大鼠心肌缺血再灌注损伤的保护作用

目的:探讨缺血后适应对大鼠急性心肌缺血再灌注损伤的保护作用.方法:球囊垫扎法制作大鼠在体急性心肌缺血再灌注模型,并利用球囊反复抽瘪-充盈方法观察缺血后适应.36只SD大鼠随机分为假手术组、缺血再灌注组、缺血后适应组,每组12只.于再灌注末处死大鼠,分别测定心功能参数、血浆心肌酶、细胞凋亡指数和心肌梗死范围;Western blot 法测定Bcl-2、Bax、Caspase-3在心肌组织中的表达.结果:缺血后适应组心功能参数较缺血再灌注组明显改善(P<0.01);血浆心肌酶谱、细胞凋亡指数明显低于缺血再灌注组(P<0.01);心肌梗死范围比缺血再灌注组减少(P<0.05);与缺血再灌注组比较,心肌组织中Bcl-2表达升高,Bax及Caspase-3表达降低(P<0.01).结论:缺血后适应能减轻心肌缺血再灌注损伤,减少缺血心肌细胞凋亡,缩小心肌梗死范围;其保护机制可能与激活RISK信号通路有关.

Protective effects of ischemic/reperfusion postconditioning on rat acute myocardial ischemia

Objective:To establish the rat acute myocardial ischemia/reperfusion model using capsule and observe the protective effects of ischemic postconditioning(IPost) on rats.Methods:Thirty-six rats were randomly divided into sham operation group,ischemia/reperfusion group(I/R group) and Ipost group(12 rats in each group),and all animals were sacrificed at the end of reperfusion.The cardiac functional parameters,plasma myocardial enzymes,apoptosis index and the scope of myocardial infarct were determined,and the levels of Bcl-2,Bax,Caspase-3 of cardiac muscular tissue were detected by Western blot.Results:Compared with I/R group,the cardiac functional parameters of Ipost group were obviously improved(P<0.01),while their plasma myocardial enzymes,apoptosis index were significantly lower and scopes of myocardial infarct were significantly less(P<0.05).The level of Bcl-2 of Ipost group was significantly higher than that of the I/R group,and the levels of Bax and Caspase-3 of Ipost group were significantly lower than those of the I/R group(P<0.01).Conclusions:The method of ligating coronary artery with capsule is fast and convenient for Ipost,which can alleviate myocardial ischemia/reperfusion injury,reduce myocardial cells apoptosis and downsize the scope of myocardial infarct.The protective mechanism is possible associated with the activation of RISK signaling pathway.