急性心肌梗死心肌细胞中Bax和Bcl-2基因的mRNA表达量及其与凋亡的关系

目的 :探讨急性心肌梗死心肌细胞中Bax和Bcl 2基因的mRNA表达量及其与凋亡的关系。方法 :新西兰兔 4 8只 ,随机分为不结扎冠状动脉的正常对照 (oh)及结扎冠状动脉后 1h ,2h ,3h ,4h ,6h ,8h及 12h共8组。TUNEL法检测梗死区心肌细胞凋亡 ,逆转录PCR法检测Bax和Bcl 2基因在心肌细胞中的mRNA表达量 ,探讨它们之间的相互关系。结果 :兔梗死区心肌细胞凋亡千分率在冠状动脉结扎后 1h开始增多 ,4h达高峰 ,其后逐渐下降 ,到 12h降至正常。Bax基因mRNA的表达量在冠状动脉结扎后 2h开始升高 ,4h达高峰 ,持续 6h后逐渐下降 ,至 12h接近正常。Bcl 2基因mRNA表达量在冠状动脉结扎后 2h开始明显下降 ,4h达最低点 ,持续 2h后开始回升 ,到 12h时已恢复到比正常高的水平。两种基因mRNA表达量的对数值之间呈负相关 ,心肌细胞凋亡数与Bac/Bcl 2基因mRNA比值呈正相关。结论 :兔梗死区心肌细胞存在明显的凋亡现象 ,Bax基因使其上调、Bcl 2基因使其下调 ,Bax/Bcl 2基因mRNA表达比值调控细胞凋亡

Expression of Bax and Bcl-2 gene mRNA and apoptosis on the cardiocyte in acute myocardial infarction in rabbits

Objective:To study the expression of Bax and Bcl 2 gene with the apoptosis on the cardiocyte of acute myocardial infarction (AMI) in rabbits.Methods: In rabbits AMI models, forty eight New Zealand rabbis were randomized into seven experimental groups. Apoptosis was detected in situ with end labeling method. The mRNA expression of Bax and Bcl 2 gene were monitored by RT PCR.Results: The permillage of apoptotic myocytes in infarct area increased at 1 h and achieved the peak at 4 h, and then decreased to the normal gradually. The amount of mRNA expression of Bax gene inceased at 2 h, and maintained the peak with in 4 h to 10 h, and then dropped to the normal. The amount of mRNA expression of Bcl 2 gene began to drop at 2 h and maintained the lowest expression with in 4 h to 6 h and then increased to the normal gradually. The significanly negative correlation was found between the logarithmic values of Bax mRNA and Bcl 2 mRNA expression in infarct myocytes A significantly positively correlation was found between the logarithmic value of the ratio of Bax mRNA to Bcl 2 mRNA and the apoptotic myocyte.Conclusion: Our results show that apoptosis of the myocytes in infarcted area is related with up regulated Bax gene and alown regulated Bcl 2 gene.