Effect of Ischemic Postconditioning on Alleviating Myocardial Ischemia-Reperfusion Injury in Rabbits

Objective To investigate the effects of ischemic postconditioning on alleviating myocardial reperfusion injury in rabbit in vivo and explore its potential mechanisms.Methods Thirty-two healthy and adult male rabbits were randomly divided into four groups(n=8 in each group): Group 1(Sham),Group 2(ischemic reperfusion),Group 3(ischemic postconditioning) and Group 4(ischemic postconditioning and 5-HD).The model of ischemic reperfusion injury was made by occluding the left anterior descending artery for 30 min and reperfusion for 60 min in rabbit heart.The index of LVSP,LVEDP,plasma creatine kinase activity and malondialdehyde content were measured and compared at baseline,the end of ischemia and after 60 min of reperfusion respectively.Myocardial ischemic and infarct size was determined at the end of the experiment.Results At 60 min of reperfusion,compared with Group 2,LVSP was significantly higher in Group 3(P0.05);LVEDP,plasma CK activity,Plasma MDA content and myocardial infarct size were significantly reduced(P0.05).There were no differences in LVSP,LVEDP,CK activity,MDA content and infarct size between Group 2 and Group 4.Conclusion Ischemic postconditioning can alleviate the reperfusion injury via opening mitochondrial ATP-sensitive potassium channels.