三羟基异黄酮对兔缺血心肌的保护作用

目的探讨三羟基异黄酮(GST)对缺血/再灌注(I/R)心肌的保护效果及可能机制。方法结扎雄兔冠脉左前降支建立心肌I/R模型:心肌缺血40 min,然后再灌注2 h。分4组:Sham组:冠脉不结扎;I/R组;GST+I/R组:心肌缺血前5 min静脉注入1.0 mg/kg GST;Vehicle+I/R组:心肌缺血前5 min静脉注入1 mL二甲基亚砜。检测血清乳酸脱氢酶及肌酸激酶活性,再灌注结束后通过Evans蓝-TTC染色判断心肌梗死范围,TUNEL法检测心肌细胞凋亡。结果与I/R组及Ve-hicle+I/R组相比,GST+I/R组心肌梗死范围、心肌酶活性及细胞凋亡指数均显著降低(P<0.01),而前两组之间无显著差异。结论心肌缺血前给予GST能有效地减轻心肌I/R损伤,抗凋亡和减少心肌细胞坏死是其发挥效应的两条途径。

Protective effect of genistein on myocardial ischemia/reperfusion injury of rabbits

Objective To explore the cardioprotective effects of genistein(GST) on myocardial ischemia/reperfusion(I/R) injury in male rabbits,and to discuss its possible mechanisms.Methods The left anterior descending coronary artery was fully occluded in anesthetized open-chest rabbits,and then they were subjected to 40 min myocardial ischemia followed by reperfusion for 2 h.The rabbits were randomly assigned to 4 groups: sham group(the coronary artery was not occluded);I/R group;GST I/R group(GST was administered intravenously 5 min prior to coronary occlusion);Vehicle I/R group(dimethylsulfoxide was administered intravenously 5 min prior to coronary occlusion).The activities of lactate dehydrogenase(LDH) and serum creatine kinase(CK) were assayed throughout the experiment.Infarct size was assessed by TTC staining,and apoptosis cardiomyocytes were detected by TUNEL staining at the end of reperfusion.Results Rabbits treated with GST showed significant reduction of infarct size and decrease of apoptotic index and the activities of LDH and CK(versus I/R group or Vehicle I/R group,P<0.01,all).No differences were observed between I/R group and Vehicle I/R group.Conclusion GST administered before ischemia exerts significant effects of protecting myocardium against I/R injury,which may contribute to its reduced myocardium necrosis and anti-apoptotic roles.