不同缺血时间窗对大鼠在体心肌缺血再灌注损伤的影响

Effects of different ischemic time on ischemic-reperfusion injury in the rat heart in vivo

目的:探讨不同缺血时间窗对大鼠在体心肌缺血再灌注损伤的影响。方法:取7~8周龄Wistar大鼠48只,雌雄各半,随机分为4组(假手术组、缺血7.5min组、缺血15min组、缺血30min组),假手术组开胸后只穿线不结扎,其余各组开胸后分别结扎左冠状动脉前降支(LAD)7.5min、15min、30min后行再灌注,术后检测大鼠心肌酶水平、心肌梗死面积、心功能情况,并行心肌病理检查。结果:与假手组比较,缺血7.5min、15min、30min组血清心肌酶CK-MB含量均明显升高(P均<0.05),缺血15min、30min组心肌梗死面积均明显增大(P均<0.01);超声心动图示缺血7.5min组心功能与假手术组相比无变化(P>0.05),缺血15min、30min组心功能较假手术组均明显下降(P均<0.05);心肌病理检查示各缺血组均有炎性细胞浸润,心肌结构损伤,缺血15min、30min组损伤更明显。结论:不同缺血再灌注时间对大鼠在体心肌损伤的影响不同。

Objective:To observe the effects of different time windows on myocardial ischemia-reperfusion injury in rats in vivo. Methods:Forty-eight Wistar rats aged 7~8 weeks with half male were randomly divided into four groups:sham-operated group,ischemic 7.5 min group,ischemic 15 min group and ischemic 30 min group.All the rats underwent thoracotomy.In ischemic groups,reperfusion was performed after ligating the left anterior descending coronary artery (LAD) for 7.5 min,15 min and 30 min respectively.Myocardial enzyme levels,infarct size and ventricular function were measured after operation.Myocardial pathological examination was also performed. Results:Compared with sham-operated group,CK-MB level in ischemic groups increased significantly (all P <0.05),and infarct size was larger in ischemic 15 min group and ischemic 30 min group (all P <0.01).Echocardiography suggested that ventricular function decreased in ischemic 15 min and 30 min group contrast with sham-operated group (all P <0.05),while there was no significant change in ischemic 7.5 min group ( P > 0.05 ).Myocardial pathological examination showed that ischemic groups had inflammatory cell infiltration and myocardial structural damage,especially in the ischemic 15 min and 30 min group. Conclusions:Different ischemia-reperfusion time has different effects on myocardial injury in rats.