The Cardioprotective Effects And Mechanisms Of Remifentanil Postconditioning On Isolated Rabbit Heart Suffering From Ischemia And Reperfusion

Objective:The Langendorff model of isolated rabbit heart was set up,To investigate the protective effects of remifentanil postconditioning against ischemia-reperfusion injury in isolated rabbit hearts;To demonstrate the cardioprotective effect of remifentanil postconditioning against myocardium injury induced by ischemia reperfusion and possible interaction with mitochondrial ATP-sensitive K+ channel in vitro.Methods:1.32 rabbits were randomly divided into 4 groups:ischemia reperfusion group,remifentanil preconditioning,remifentanil postconditioning,remifentanil pretconditioning plus remifentanil postconditioning.Ischemia reperfusion injury was induced by 30 min of global ischemia and 120min of reperfusion in isolated rabbit hearts. All hearts were perfused in the langendorff mode. The myocardial contraction and diastole functions, concentrations of lactate dehydrogenase and creatine phosphokinase in the liquid of coronary,coronary perfusion pressure and myocardial infarct size were measured.2.32 rabbits were randomly divided into 4 groups:ischemia reperfusion group, remifentanil postconditioning,5-hydroxydecanoic acid postconditioning, remifentanil postconditioning plus 5-hydroxydecanoic acid postconditioning. All hearts were perfused in the langendorff mode. The myocardial contraction and diastole functions, concentrations of lactate dehydrogenase and creatine phosphokinase in the liquid of coronary, coronary perfusion pressure and myocardial infarct size were measured.Results:1. In remifentanil postconditioning group, The myocardial contraction and diastole functions improved signifycantly, infarct size reduced remarkablely; the concentrations of creatine phosphokinase,lactate dehydrogenase in coronary effluent were lower than those in ischemia reperfusion group.2. In remifentanil postconditioning group, the cardiac functions improved signifycantly,coronary perfusion pressure and the infarct size decreased,the concentrations of creatine phosphokinase,lactate dehydrogenase in coronary effluent were lower those that in ischemia reperfusion group. The cardioprotective effect of remifentanil postconditioning could be antagonized partly by a mitoKATP channel closurer(5-hydroxydecanoic acid).Conclusion:1.â‘ remifentanil postconditioning can protect the rabbit heart from ischemia reperfusion injury by improving myocardial systolic-diastolic function and preserving the myocardial and decreasing infarct size.â‘¡The results showed that remifentanil postconditioning group had well protective effects on myocardial ischemia reperfusion injury as well as remifentanil preconditioning group.2.â‘ The selective ATP-sensitive potassium channel antagonist 5-hydroxydecanoic acid can reverse partly the cardioprotective effects of remifentanil postconditioning.â‘¡The mechanism of the cardioprotection of remifentanil postconditioning may be to activate mitochondrial ATP-sensitive potassium channel.