缺血后处理对急性缺血再灌注心肌生化指标的影响

EFFECT OF ISCHEMIC POSTCONDITIONING ON MYOCARDIAL BIOCHEMICAL INDEXES AFTER ACUTE ISCHEMIC INJURY

①目的通过体内兔心肌缺血再灌注模型比较缺血预处理、缺血后处理对急性缺血再灌注损伤心肌生化指标的影响.②方法24只兔随机分为3组.对照(con)组:结扎冠状动脉40 min,再灌注180 min.缺血预处理(pre-con)组:3次短暂结扎冠状动脉(闭塞5 min,再灌注10 min,循环3次),其余同对照组.缺血后处理(post-con)组:结扎冠状动脉40 min,再通30 s,结扎30 s,重复3次,再灌注180 min.3组均在缺血及再灌注同时行心电图和心肌酶检查,再灌注末抽血离心测定超氧化物歧化酶(SOD)、丙二醛(MDA).实验结束,速取心脏处理测定梗死面积.③结果和对照组相比,pre-con和post-con组再灌注各个时间点肌酸磷酸激酶(CPK)均降低(F＝40.13～91.26,q＝5.52～18.67,P＜0.05、0.01);pre-con和post-con组坏死面积占总面积之比均小于对照组(F＝62.36,q＝13.44、13.90,P＜0.01);post-con组血清中SOD的含量高于对照组,MDA的含量低于对照组(F＝17.00、40.75,q＝3.46、12.76,P＜0.01).④结论缺血后处理和缺血预处理具有相似的缺血心肌保护作用,缺血后处理的机制部分可能是通过减少自由基损伤实现的.

Objective To compare and evaluate the cardio-protective effects of postconditioning and preconditioning.Methods In anesthetized rabbits, the left anterior descending artery （LAD） was occluded for 40 min and reperfused for three hours. In the pre-conditioning（pre-con） group （n=8）, the LAD was occluded for 5 min and reperfused for 10 min before the prolonged occlusion. In the post conditioning（post-con） group （n=8）, three cycles of 30 seconds＇ reperfusion and 30 seconds＇ LAD reocclusion were performed before three hours of reperfusion. Results Infarct size was significantly less in the pre con and post-con groups than that of the controls（F=40.13-91.26; q=5. 52-18.67; P〈0.05,0.01）. The levels of CPK in the pre-con and post-con groups were significantly less than in the controls at three different times. SOD, an antioxidant ,was significantly higher at three hours of reperfusionin post-con group （F=62.36;q=13.44,13.90;P〈0.01） , while lower in MDA levels（F=17.00,40.75;q=3.46,12.76;P〈0.01）. Conclusion Post-conditioning is as effective as pre-conditioning in reducing infarct size and serum CPK. Post-conditioning may be partly due to the reduction of the injury of free radicals.