Role of free radicals on the reperfusion injury of ischemic heart -study with radical scavengers-

目的：研究自由基在各种实验性心脏缺血再灌注损伤中的作用。采用自旋捕集剂POBN的电子自旋共振（ESR）方法检测大鼠和犬缺血-再灌注心脏再灌注后30 s ~ 5 min的自由基.大鼠和犬心肌缺血-再灌注模型心肌肌浆网Ca^++-ATPase活性及其组成蛋白的降解早于缺血-非再灌注模型.在灌流的大鼠心脏和离体心肌细胞中，用氯化铈作为过氧化氢的反应物，观察线粒体和内皮细胞产生自由基的情况，并进行超微结构观察.超氧化物歧化酶（SOD）和ACE抑制剂（丙氨蝶呤）能明显改善犬顿抑心脏（缺血15 min再灌注60 min）的收缩功能和SR功能。结论：自由基的产生是再灌注损伤的起始因素之一。

Object :We studied the role of free radicals on the reperfusion injury in the various experimental models of ischemic heart.Results :1. We could detect the free radicals with electron spin resonance (ESR) method using spin trapping agent, POBN,in the rat and dog models of ischemia-reperfused heart from 30 sec to 5 min after reperfusion.2. Ca^<++>-ATPase activity of sarcoplasmic reticulum (SR) and its composing protein was earlier degradated in the ischemia-reperfused heart than ischemia-nonreperfused heart in the rat and dog models.3. In the perfused rat heart and isolated myocyte, free radical generations from mitochondria and endothelial cell were detected visually using Cerium chloride, reactant to the hydrogenperoxide, with ultrastructural observation.4. In the stunned heart of the dog model (15 min ischemia followed by 60 min reperfusion), contractile function and its SR function were more improved with treatment of superoxide dismutase (SOD) and ACE-inhibitor (alacepril).Conclusion :Free radial generation was one of the initial factors of the reperfusion injury.