[Oxygen free radical generation in ischemic-reperfused myocardium of rat in vivo].

Many studies have provided indirect evidence that there is a relationship between oxygen free radical and myocardial ischemic-reperfusion injury. In this study, we applied ESR spectroscopy to measure oxygen free radical generation in the acutely ischemic-reperfused heart of rat in vivo. The experimental model was established by 45 min ligation of the left anterior descending coronary artery (LAD) and 10 min reperfusion in vivo. The myocardial samples taken for ESR measurement were fresh-freezing tissue pieces. Meanwhile, the tissue ultrastructure was observed. We also observed the protective effect of superoxide dismutase (SOD) on myocardial ischemic-reperfusion injury. The results showed: 1. Large amounts of oxygen free radical were generated in the course of postischemic reperfusion. The amount of oxygen free radical produced in this process was positively related to the extent of myocardial damage. Oxygen free radical was at least one of the major cause of rat myocardial reperfusion injury observed in this experiment. 2. SOD could scavenge oxygen free radical and prevent or reduce reperfusion injury of rat heart in vivo.