表没食子儿茶素没食子酸酯对缺血再灌注心肌细胞凋亡的作用

目的：观察表没食子儿茶素没食子酸酯（EGCG）对缺血再灌注损伤大鼠心肌细胞凋亡的影响。 方法： 采用结扎大鼠左冠状动脉前降支30 min，然后松开再灌注60 min的方法，复制大鼠心肌缺血再灌注损伤模型。实验分假手术组、缺血再灌注组（IR）、EGCG不同剂量治疗组和丹参（SM）组。用原位缺口末端标记法（TUNEL）检测心肌凋亡细胞，用链酶亲和素-生物素-酶复合物（SABC）免疫组化法检测凋亡相关基因Bcl-2和Bax蛋白表达。 结果： 在假手术组未发现凋亡细胞，IR组细胞凋亡明显，Bcl-2和Bax蛋白表达增加，但以Bax更明显，Bcl-2/Bax值显著低于假手术组（P<0.01）；EGCG组凋亡细胞明显少于IR组，Bcl-2表达显著大于而Bax表达显著少于IR组，Bcl-2/Bax值显著高于IR组（P<0.01）。 结论： EGCG能明显抑制IR引起的心肌细胞凋亡，其作用机制可能与下调Bax和上调Bcl-2蛋白表达，提高Bcl-2/Bax值有一定关系。

Effect of epigallocatechin gallate on cardiomyocyte apoptosis induced by ischemia-reperfusion in rats

AIM: To observe the effects of epigallocatechin gallate (EGCG) on cardiomyocyte apoptosis induced by ischemia - reperfusion (IR) in rats. METHODS: The left anterior descending branch of coronary artery was ligated for 30 min and reperfused for 60 min to make a the myocardial ischemia - reperfusion model in rats. The experiment was divided into five groups: sham, ischemia/reperfusion (IR), EGCG (10 mg/kg and 20 mg/kg) and salvia miltiorrhizae (SM, 100 mg/kg) group. The apop-totic cardiomyocytes were detected by in situ end labeling method, and the expressions of Bcl - 2 and Bax were shown through im-munohistochemistry method. RESULTS: There was no apoptosis myocardial cell in sham operation group. The apoptosis index and expression of bax significantly increased, and bcl - 2/bax reduced in IR group ( P < 0.01). In EGCG - treated group, however, the changes above were obviously alleviated ( P < 0.01). CONCLUSION: EGCG significantly inhibits cardiomyocyte apoptosis in ischemia - reperfusion rat hearts. The possible mechanism is to raise the ratio of Bcl - 2/Bax proteins by increasing in the expression of bcl - 2 gene and decreasing in the expression of bax gene.