丹参多酚酸盐对大鼠心肌缺血再灌注后心肌细胞凋亡的抑制作用及机制研究

Inhibitory Effect of Salvianolate on Myocardial Apoptosis after Myocardial Ischemia-reperfusion Injury in Rats and Its Mechanism

目的研究丹参多酚酸盐对大鼠心肌缺血再灌注损伤后心肌细胞凋亡的抑制作用及其机制。方法通过夹闭左冠状动脉前降支复制心肌缺血再灌注大鼠模型,设假手术组、模型组和丹参多酚酸盐各剂量组(分别予10mg/kg、20mg/kg、40mg/kg),每组20只。观察心电图波动情况,2,3,5-氯化三苯基四氮唑(TTC)染色法检测心肌梗死面积;苏木素-伊红(HE)染色法进行心肌组织病理学检查;缺口末端标记法(TUNEL)观察心肌细胞凋亡,蛋白质免疫印迹(western blotting)法检测其凋亡相关蛋白表达。结果与模型组比较,丹参多酚酸盐各剂量组心电图明显改善。与假手术组比较,模型组大鼠心肌组织梗死面积明显升高(P <0.01);丹参多酚酸盐20mg/kg组、40mg/kg组大鼠心肌组织梗死面积较模型组显著降低(P <0.05或P <0.01)。丹参多酚酸盐各剂量组大鼠心肌组织病变较模型组明显改善。模型组大鼠心肌细胞凋亡指数(AI)较假手术组显著升高(P <0.01);丹参多酚酸盐20mg/kg组、40mg/kg组AI较模型组显著降低(P <0.05或P <0.01)。模型组大鼠心肌组织Bcl-2、Bax蛋白、激活型Caspase-3蛋白较假手术组显著上调表达(P <0.05或P <0.01),Bcl-2/Bax比值较假手术组显著降低(P <0.01)。与模型组比较,丹参多酚酸盐20mg/kg组、40mg/kg组抑凋亡蛋白Bcl-2表达显著上调,促凋亡蛋白Bax表达显著下调(P <0.05或P <0.01),Bcl-2/Bax比值提高(P <0.01),促凋亡蛋白激活型Caspase-3蛋白表达显著下调(P <0.05或P <0.01)。结论丹参多酚酸盐对缺血再灌注后心肌细胞凋亡具有抑制作用,而调节凋亡相关蛋白(Bcl-2、Bax、激活型Caspase-3)表达可能是其重要的分子机制。

Objective To investigate the inhibitory effect and mechanism of Salvianolate on myocardial apoptosis after myocardial ischemia-reperfusion injury (MIRI) in rats.Methods The myocardial ischemia-reperfusion model was established by clamping the left anterior descending coronary artery.The rats were divided into sham group,model group,and Salvianolate groups (10,20,40 mg/kg,n =20 in each group).The changes of electrocardiogram (ECG) in each group were monitored.The infarct size was detected by 2,3,5 triphenyltetrazolium chloride (TTC) staining method.The myocardial histopathological changes was observed by Hematoxylin Eosin (HE) staining.The apoptosis of cardiomyocytes was observed by TUNEL.The expression of apoptosis-related proteins was detected by western blotting.Results Compared with model group,The ECG in Salvianolate (10,20,40 mg/kg) groups were significantly improved, especilly in the Salvianolate 40 mg/kg group.The myocardial infarct size in Salvianolate 20 mg/kg group and Salvianolate 40 mg/kg group were significantly decreased (P <0.05 or P <0.01).The myocardial histopathological changes and myocardial cardiomyocyte apoptosis were significantly improved and the apoptotic index (AI) were significantly decreased (P <0.01).The expression of Bcl-2 protein was significantly increased,and the expressions of Bax,and cleaved Caspase-3 were significantly decreased (P <0.05 or P < 0.01).The ratio of Bcl-2/Bax was significantly increased (P <0.01).Compared with the model group,the expression of anti apoptotic protein Bcl-2 was significantly up-regulated in the Salvianolate 20 mg/kg group and 40 mg/kg group,and the pro apoptotic protein Bax expression was significantly down-regulated (P <0.05 or P <0.01).The Bcl-2/Bax ratio was increased (P <0.01),and the expression of proapoptotic protein-cleaved Caspase-3 protein was significantly down-regulated (P <0.05 or P <0.01).Conclusion Salvianolate has an inhibitory effect on cardiomyocyte apoptosis after MIRI,and regulation of apoptosis-related proteins such as Bcl-2,Bax,and activated Caspase-3 may be an important molecular mechanism.