不同时段的心肌缺血后再灌注损伤与心肌细胞凋亡的实验研究

目的　探讨实验性不同时段的心肌缺血后再灌注损伤是否致心肌细胞凋亡、凋亡率的大小及不同的缺血时间与凋亡率的关系。方法　阻断左冠状动脉的左室支建立心肌缺血模型 ,达到预定的缺血时间后 ,使血管再通 ,建立心肌的缺血再灌注模型。采用透射电镜、原位末端探针标记、图像分析和统计处理对缺血灌注损伤区心肌细胞的损伤情况进行研究。结果　电镜观察和原位未端标记 (TUNEL)检测发现在经历了不同的缺血时间后 ,再灌注均可致心肌细胞凋亡 ,但不同的缺血时间后再灌注致心肌细胞的凋亡率不同 ,实验Ⅰ～Ⅲ组平均凋亡率分别为 3 2 7%、18 4 3%和 2 0 2 8%。缺血时间越长凋亡率越高。结论　心肌缺血再灌注损伤的发生与凋亡机制有关 ,且凋亡率的大小在一定的时间段内可能与心肌的缺血时间呈正相关

Experimental research on the relationship between cartdiomyocyte apoptosis and ischemic-reperfusion injury of different duration in rabbits

Objective To explore cardiomyocyte apoptosis, apoptosis rate and the relationship between the apoptosis rate and different duration of ischemia in experimental rabbits Methods Myocardial ischemic model was built by blocking left ventricle branche of left coronary artery, as the scheduled time of ischemia reached, the blocked blood vessel was recanalized to set up model of myocardial ischemia reperfusion Electronic microscope, TUNEL, image analysis and statistic treatment were used for the researches of myocardial apoptosis in the ischemia repefusion injury region Results By electronic microscope and TUNEL, obvious cardiomyocyte apoptosis caused by reperfusion were observed after ischemia in the region of ischemic reperfusion injury, but reperfusion after the different duration of ischemia leaded to different apoptosis rate Average apoptosis rates of groups Ⅰ～Ⅲ were 3 27%, 18 43%, 20 28% respectively With the ischemia time prologed, the apoptosis rate was increased Conclusion Cardiomyocyte apoptosis involved in the mechanism of the myocardial ischemia reperfusion injury and the apoptosis rate is positively correlated to the duration of ischemia during a given time