银杏叶提取物对急性心肌梗死大鼠心肌细胞的保护作用

Protection of Ginkgo biloba extract on cardiomyocyte after acute myocardial infarction in rats

目的:探讨银杏叶提取物(EGb761)对急性心肌梗死(AMI)大鼠心肌细胞的保护作用。方法:雄性SD大鼠30只,随机均分为假手术组(A组)、AMI组(B组)和EGb761组(C组)。C组腹腔注射EGb761(20 mg/kg),A组和B组腹腔注射等容量的生理盐水,每天1次,共3天。实验大鼠于第3天开胸,A组冠脉下穿线但不结扎冠状动脉,B组和C组结扎冠状动脉左前降支,制备AMI模型。实验终点,取腹主动脉血测定血清中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,观察各组大鼠心肌细胞凋亡指数(AI)、细胞色素C(Cytc)和Caspase-9表达以及线粒体膜电位的变化。结果:与B组相比,C组SOD活性明显增高,MDA含量显著下降,AI及Caspase-9表达明显降低,Cytc胞质表达显著减少而线粒体表达显著增加,线粒体膜电位明显升高(P<0.01)。结论:EGb761可减少AMI缺血区心肌细胞凋亡,其机制可能与减轻氧化应激,保护线粒体功能,减少Cyt-c释放入胞质有关。

Objective：To study the protective effect of Ginkgo biloba extract（EGb761） on cardiomyocyte after acute myocardial infarction（AMI） in rats.Methods：Thirty male Sprague-Dawley rats were randomly divided into sham group（group A）,AMI group（group B）,EGb761 group（group C）,ten in each group.In group C,EGb 761（20 mg/kg） was injected intraperitoneally,in group A and group B,normal saline（20 mg/kg） was injected intraperitoneally.All the liquid was injected once a day for 3 days.The animal model was established by ligating left anterior descending coronary artery on the third day.The operation in group A was similar to group B except for ligating the left anterior descending coronary artery.At the end of experiment,the levels of the superoxide dismutase（SOD）,malondialdehyde（MDA）,apoptotic index（AI）,mitochondrial membrane potential and the expression of Cyt-c and caspase-9 were measured.Results：Compared with group B,the contents of MDA,AI,caspase-9 and cytoplasmic Cyt-c were significantly lower in group C（P0.01）.The level of SOD,the expression of mitochondrial Cyt-c and mitochondrial membrane potential were significantly higher in group C（P0.01）.Conclusions：EGb 761 can decrease apoptosis in ischemic myocardium after acute myocardial infarction.The mechanism is possibly that EGb 761 can decrease oxidative stress,protect mitochondrial functions and reduce the release of Cyt-c from mitochondria to cytoplasma.