心肌肥大和心力衰竭大鼠心肌细胞凋亡及Bax和Bcl-2的表达

Cardiomyocyte apoptosis and the expression of Bax, Bcl-2 in cardiamyocyte hypertrophy and heart failure rats

目的:探讨心肌肥大和心力衰竭(心衰)大鼠心肌细胞凋亡及Bax和Bcl-2蛋白表达的变化。方法:24只健康雄性SD大鼠随机分为假手术组(对照组)、心肌肥大组、心衰组,每组8只。心肌肥大组和心衰组均采用缩窄腹主动脉构建模型。假手术组和心肌肥大组大鼠于第4周处死,心衰组大鼠于第12周处死。分别检测各组血流动力学和左室肥大指标,TUNEL法检测心肌细胞凋亡,免疫组织化学法检测心肌Bcl2和Bax的表达。结果:心力衰竭组与心肌肥大组比较,左室收缩末压、左室舒张末压、心室内压变化最大速率差异均有统计学意义(P<0.01或0.05)。心衰组较心肌肥大组心肌细胞凋亡增加,Bax表达增加,Bcl-2表达减少(P<0.01)。结论:心肌细胞凋亡在心脏由心肌肥大向衰竭的转变过程中起着重要的作用,并与凋亡蛋白Bax和Bcl-2表达改变有关。

Aim: To explore the role of apoptosis and expression of Bcl-2 and Bax in rats with hypertrophy and heart failure(HF).Methods: Twenty-four male SD rats were divided randomly into sham-operated control group,HF group,and cardiomyocyte group with eight rats in each group.Pathological models of cardiomyocyte hypertrophy and HF were prepared by compressing of abdominal aorte of rats partly. Four weeks later, rats of sham-operated control group and hypertrophy group were killed.Twelve weeks later, rats in heart failure group were killed.The hemodynamic parameters and hypertrophy were detected. Apoptotic cells were detected in situ using TUNEL.The Bax and Bcl-2 proteins of cardiomyocyte were detected using immunohistochemistry. Results: Compared with hypertrophy group,p_ LVES,p_ LVED,and ±dp/dt_ maxof heart failure group significantly changed(P<0.01 or 0.05). Compared with sham-operated control group, cardiomyocyte apoptotic events increased,expression of Bax increased,whereas that of Bcl-2 decreased in cardiomyocyte hypertrophy group(P<0.01). Compared with cardiomyocyte hypertrophy group, cardiomyocyte apoptotic events increased,expression of Bax increased, whereas that of Bcl-2 decreased in HF group(P<0.01). Conclusion: Cardiomyocyte apoptosis plays an important role during transition from ventricular hypertrophy to heart failure,which is related to the changes of Bax and Bcl-2 expression.