Protective Effect of Puerarin Preconditioning on Myocardial Ischemia-reperfusion Injury in Isolated Rat Hearts

Objective To study the protective effect of puerarin preconditioning on myocardial ischemia-reperfusion injury in isolated rat hearts,by establishing the langendǒrff-perfusion model of rat hearts and to try to find out the possible mechanism of this protective effect.Methods Isolated langendǒrff hearts of rats were used.50 male Sprague-Dawley rats were randomly divided into five groups: Control group,ischemia-reperfusion group, ischemic preconditioning group,low-dose-puerarin preconditioning group and high-dose-puerarin preconditioning group.Cardiacfuction,CK,MDA,SOD,NO and myocardial histopathological observation were observed respectively during the study.Results Compared with control group,ischemia-reperfusion group caused a decrease in heart rate,left ventricular systolic pressure and the maximal rate of rise/decrease of left ventricular pressure and increase in left ventricular end diastolic pressure.CK leakage and MDA content in myocardium were also enhanced.NO and SOD content in myocardium were decreased.Ischemic preconditioning group and puerarin preconditioning group improved cardiac function,reduced CK leakage and MDA content and increased NO and SOD content in myocardium significantly.Meanwhile the myocardial histopathological damage was alleviated.Compared with low-dose-puerarin group,the protective effect of high-dose-puerarin group was more obvious.Conclusion Puerarin preconditioning just as ischemic preconditioning can protect myocardium from ischemia-reperfusion injury and lipid peroxidation,improve cardiac function and increase myocardial tolerance to the subsequent prolonged ischemia.It appears that the protective effect of puerarin preconditioning is related with the increase of SOD and NO in the myocardium.The former can scavenge oxygen free radicals and the latter can expand coronary arteries.The more puerarin was used,the better function was founded.