Effect of nicorandil-KATP channel opener on ischemia reperfusion in myocardium of rat

Objective:To investigate the effect of pretreatment with nicorandil(NTC)-KATP channel opener on ischemiareperfusion(IR) rat in myocardium of rat.Methods:The snare for occlusion and reperfusion had been put into the anterior descending coronary artery in 60 rats,which were divided into four groups: ischemiareperfusion(IR) group,nicorandil(NIC) group,glibenclamide(GLI),KATP channel inhibitor+NIC group,GLI group.The activity of creatine kinase and lactate dehydrogenase in plasma and the infarct size were measured.The episode of arrhythmias was monitored.The ultrastructural changes of the myocardium were observed under electron microscope.Results:Compared with IR group,the plasma concentration of CK and LDH significantly reduced(P0.05 all),the infarct size significantly reduced [(52.9±14.2)% vs.(20.3±6.4)%,P0.005 ] but the incidence of myocardial arrhythmias not significantly reduced in nicorandil group,these change were no significantamong GLI+NIC group,GLI group and IR group.Conclusion:Nicorandil-nonspecial KATP channel opener may have part of myocardial protective effect of ischemic preconditioning.It is suspected that one of family of KATP channel plays a primary role in myocardial protective effect of ischemic preconditioning.