Protective Effects of HOE694 on Endogenous Free Radical Induced Myocardial Injury in Isolated Rabbit Hearts

Objective To observe the protective effects of the specific Na~+/H~+ exchange inhibitor HOE694 on myocardial injury induced by endogenous free radical in isolated rabbit hearts.Methods The isolated rabbit hearts were perfused in a Langendorff model.The hearts were perfused with xanthineoxidase(XO,2 U/L)and hypoxanthine(HX,0.06 mmoL/L)to induce myocardial injury.Left ventricular pressure(LVP),the frist derivative of LVP(+dp/dtmax),left ventricular end-diastolic pressure(LVEDP)and heart rate(HR)were recorded.Coronary flow(CF)and the activity of creatine kinase(CK)in coronary effluent were measured by timed collection of coronary effluent.At the end of the reperfusion,the content of malondialdahyde(MDA)in cardiac tissue was measured.Results Perfusion with HX+XO for 10 min caused a significant impairment of cardiac function,as shown by a decrease in LVP and +dp/dtmax,and an increase in LVEDP,the relase of CK and the content of MDA.Pretreatment with HOE694(0.1,0.3 μmoL/L)for 10 min produced a significant improvement of cardiac function and a decrease in the release of CK and the content of MDA.Conclusion HOE694 protects heart against injury induced by HX + XO in isolated rabbit hearts.