早期冠状动脉搭桥术对犬急性心肌梗死的范围和肾素系统的影响

Effect of early coronary artery bypass graft on infarction scope and renin angiotensin system An experimental study on dog in acute myocardial infarction models

目的:探讨犬急性心肌梗死(AMI)早期冠状动脉搭桥对心肌梗死(MI)范围和心肌局部肾素系统即血管紧张素与肾素活性(RA)的影响及其意义。方法:结扎犬冠状动脉前降支制备MI模型(30只)。分别在MI后1,2,4及6周行冠状动脉搭桥作为实验组,其中第2周4只,其余每组6只;对每个实验组分别设立MI不搭桥对照组,每组2只。8周后开胸切取心脏分别测量MI范围,每只犬分别切取梗死区标本及正常心肌标本,样本采用放射免疫方法测定MI心肌局部RA及血管紧张素Ⅱ(AngⅡ)。结果:每个实验组各存活4只,对照组均存活。1,2周实验组较4,6周实验组及对照组MI范围明显减小(P<0.05)。对照组RA及AngⅡ含量明显高于所有实验组及正常心肌(P<0.01),4,6周实验组RA及AngⅡ含量明显高于1,2周实验组及正常心肌(P<0.05)。结论:犬AMI早期冠状动脉搭桥可以明显改善心肌缺血,减少心肌局部RA及减少AngⅡ的分泌,从而减轻AngⅡ对局部心肌的损害。尤其2周内冠状动脉搭桥可以最大限度减轻RA及AngⅡ对局部心肌的损害,并可以减少MI范围。

Objective：To investigate the effect of early coronary artery bypass graft （CABG） on myocardial infarction（MI） scope and renin angiotensin system at infracted border zone （IBZ） using dog with acute （MI） model. Method： 30 dogs were randomly assigned into experimental group （n = 22） and control group （n = 8 ）. The experimental group were further divided into 1 week （ n = 6） ,2 week （ n = 4）, 4 week （ n = 6） and 6 week （ n = 6） groups according to the time of CABG after the ligation of LADs. Control groups without CABG were established for the 4 experimental groups, 2 for each. MI scope and level of rennin activity were measured with radio immunity assay 8 weeks after the first surgery.Result：4 dogs of every experimental group and all dogs of control groups survived to the end of the study. MI scope in 1 week and 2 week groups was smaller than that in 4 week and 6 week groups and all control group （ P 〈 0.05）. The level of renin activity in all control group increased significantly compared with that in all experienmental groups and normal myocardium （P 〈 0.01 ）. The level of renin activity in 4th week and 6th week CABG increased significantly compared with that in 1 week and 2 week groups and normal myocardium（ P 〈 0.05）. Conclusion：CABG within two weeks after MI could teduse the impairment of renin activity on regional myocardium and diminish MI scope in dog MI model.