预缺血对大鼠心肌缺血再灌注凋亡的影响

Effect of Ischemic Preconditioning on Ischemia/Reperfusion Induced Cardiomyocy te Apoptosis

为观察大鼠心肌缺血再灌注的致凋亡作用和再灌注早期不同阶段中性粒细胞浸润与凋亡的关系及预缺血对凋亡的影响 ,制备在体大鼠心肌缺血再灌注模型 ,实验分为四组 :缺血 +1h再灌注组、缺血 +2h再灌注组 ,缺血 +3h再灌注组及预缺血组 ,观察分析心功能、梗死面积、中性粒细胞计数、心肌髓过氧化物酶活性及凋亡指数等指标。结果发现 ,缺血再灌注明显引起心脏功能损伤、中性粒细胞浸润和心肌细胞凋亡 ,且随再灌注时间延长而加重 ,预缺血明显减轻其损伤并抑制凋亡。心肌细胞凋亡与中性粒细胞浸润存在显著正相关关系。结果提示 ,预缺血可通过减轻凋亡对心肌发挥保护作用。

Aim To elucidate whether ischemia and reperfusi on can induce cardiomyocytes apoptosis and the relation between polymorphnuclear n eutrophils (PMN) infiltration and cardiomyocytes apoptosis. The effect of ische mic preconditioning on apoptosis was also investigated. Methods Forty eight male Wistar rats were ra ndomly assigned to one of the following four groups: I+1h R group, I+2h R group , I+3h R group and IP group. The following variables were measured: cardiac fu nction, infarct size, PMN counts, myocardial myeloperoxidase activity and ap optotic cell in dex. Results Ischemia and reperfusion caused obvio us cardiac function injury, PMN infiltration and cardiomyocytes apoptosis, and heart injury increased as the reperfusion continued; ischemic preconditionin g significantly reduced heart injury and apoptosis. Correlative analysis betwee n PMN count and apoptotic index suggested a significant positive correlation ex isted between PMN infiltration and cardiomyocyte apoptosis (r=0 .943,P<0.001). Conclusion Ischemic pr econditioning significantly reduced PMN infiltration and attenuated myocyte apop tosis.