The Mechanism of Protective Effect of Puerarin on Myocardial Ischemic Reperfusion Injury in Rats

Objective:To investigate the role of mitochondrial KATP channel(mitoKATP) in the protective effect of puerarin(PUE) on myocardial ischemia-reperfusion injury in rats.Methods: Rat heart ischemia-reperfusion injury(I/R) models were induced by occluding the left anterior descending coronary artery for 45 min and reperfusion for 120 min.Fifty-five rats were randomly divided into five groups(11 in each):(1) Group sham(did not receive operation);(2) group I/R;(3) group PUE(received PUE at a dose of 100 mg/kg intravenously 5 min before ischemia);(4) group P5D(received 5-hydroxydecanoate,a mitoKATP specific inhibitor,at a dose of 5 mg/kg intravenously 15 min before ischemia and PUE treatment at 5 min before ischemia);and(5) group 5-HD(received 5-hydroxydecanoate alone 15 minutes before ischemia).TTC dyeing was used to determine the myocardial infarction size.Cardiac myocytes apoptosis was detected by using TUNEL.Creatine kinase activity(CK) in serum was measured simultaneously.Results: Infarct size,cardiomyocytes apoptosis and CK activity in serum of group I/R were obviously higher than those in group sham(P0.05 or P0.01).Compared with group I/R,all these parameters in PUE groups were significantly lower(P0.05 or P0.01).While,in group P5D,all these parameters were significantly higher than those in group PUE.There was no significant difference found among the parameters of groups P5D,I/R and 5-HD.Conclusions: Preconditioning with puerarin can significantly reduce myocardial ischemia-reperfusion injury in rats.The protective effect of puerarin to myocardium is partly via opening the mitoKATP channel.