缺血预处理对猪冬眠心肌细胞凋亡及Bcl-2、Bax表达的影响

The effect of ischemic preconditioning on myocyte apoptosis and the expression of Bcl-2 and Bax in hibernating myocardium

目的探讨缺血预处理对冬眠心肌细胞凋亡及Bcl-2、Bax表达的影响。方法18只小型中国家猪随机分为3组:对照组(CON组)、冬眠心肌组(HM组)、缺血预处理组(IP组)。采用末端标记技术(TUNEL)测定细胞凋亡,免疫组化方法检测Bcl-2、Bax蛋白表达,透射电子显微镜观察心肌细胞超微结构。结果HM组中Bcl-2蛋白表达较CON组显著增加,在IP组,Bcl-2蛋白表达较HM组进一步升高;在HM组Bax蛋白表达高于CON组,Bax蛋白表达在HM组I、P组无统计学差别。TUNEL显示,CON组极少心肌细胞凋亡,HM组细胞凋亡较CON组增多,IP组细胞凋亡较HM组减少。结论缺血预处理可能通过增加Bcl-2蛋白表达来减少冬眠心肌细胞凋亡的发生。

Objective To explore the effect of ischemic preconditioning on myocyte apoptosis and the expression of Bcl - 2 and Bax in hibernating myocardium. Methods A total of eighteen little domestic Chinese pigs were divided into three groups randomly： control （CON）, hibernating myocardium （HM） and ischemic preconditioning （IP）. The expressions of Bcl - 2 and Bax were detected by immunohistechemistry separately. The myecyte apoptosis was evaluated by TUNEL. The structural changes of HM were observed under electron microscope. Results Immunohistochemistry showed the positive rates of Bcl - 2 and Bax were significantly increased in HM group （ P 〈 0.05）. The positive rate of Bcl - 2 was higher in IP group than in HM group （ P 〈 0.05）, but IP had no effect on protein synthesis of Bax. TUNEL showed the apoptsis rate was low in CON group, increased in HM group and less markedly increased in IP group. Conclusion Ischmie preconditioning can increase Bcl - 2 expression and reduce apoptosis in hibernating myecardium.