摘要
目的:探讨大鼠心肌缺血再灌注后不同时相心肌细胞凋亡情况及其与缺血再灌注的关系,并进一步探讨心肌细胞凋亡在心肌缺血再灌注损伤中的可能作用。方法:64只SD大鼠随机分为5组:对照组(假手术45 min、105 min、165 min、225 min,各时间点n=8),心肌缺血45 min组(I45 min,n=8),心肌缺血45 min后再灌注1 h、2 h、3 h组(I／R1 h、I／R2 h、I／R3 h,各时间点n=8),分别在各时点处死大鼠取材。应用DNA琼脂糖凝胶电泳分析与透射电镜的检测心肌细胞凋亡的改变。结果:DNA琼脂糖电泳分析显示,I／R2 h组、I／R3 h组出现凋亡特征性“梯状电泳带”而对照组、L45 min组及I／R1 h组均未见凋亡带谱。透射电镜检测显示,对照组、I45 min组、I／R1 h组均未见到凋亡的心肌细胞,I／R2 h组、I／R3 h组心肌细胞染色质凝聚、边集、核膜完整,显示出典型的凋亡特征。结论:心肌缺血再灌注可导致心肌细胞凋亡,心肌细胞凋亡因缺血再灌注不同时相而变化;心肌细胞凋亡在大鼠心肌缺血再灌注损伤的病理生理过程中起重要作用;大鼠心肌缺血后再灌注可促发或加速心肌细胞凋亡。
Objective：To compare the timing and extent of apoptosis in both ischemic and reperfused myocardium in an in vivo rat model, to investigate the possible molecular mechanism of ischemia/reperfusion-induced apoptosis in cardiomyocytes. Methods：64 SD rats were divided randomly into 5 group： Control group（sham-operated observing for 45 min.105 min.165 min and 225 rain, n = 8 for each time-point ）, I45min （group 45 min of ischemia）, I/R1 h （group 45 min of ischemia followed by 1 h reperfusion）, I/R2 h group and I/R3 h group. The rats were sacrificed at each time-point （n=8 for each time-point）. The cardiomyocytes of each groups were taken for detecting apoptosis of cardiomyocytes by DNA gel electrophoresis and transmission electron microscopy （TEM）. Results： Gel electropboresis of DNA analysis in I/R2 h and I/R3 h group showed typical ＂ladder＂ break and DNA extracted from the cardiomyocytes in control group, I45 min group and I/R1 h group presented no ＂ladder＂ break. TEM examination showed that the apoptosis cardiomyocytes was not seen in control group,I45min group and I/R1 h group. The apoptosis occurred during 45 min of ischemia followed by 2h reperfusion, and further developed during the 3h reperfusion period. It showed that characteristics of myocyte apoptosis episodes, included intact nuclear membrane, condensed chromatin and increased electron denies. Condusion：In these animal studies in vivo, it indicate that myocardial ischemia and reperfusion can induce apoptosis of cardiomyocytes; the number of apoptosis myocytes varied with different duration of myocardial ischemia and reperfusion. Apoptosis is a significant contributor to myocardial cell death as a result of ischemia and reperfusion injury.
出处
《中国临床医学》
北大核心
2006年第4期549-551,共3页
Chinese Journal of Clinical Medicine
关键词
心肌细胞
缺血再灌注
凋亡
Cardiomyocytes
Ischemia and reperfusion Apoptosis
