Objective:To investigate the protective effect of preconditioning with Puerarin on myocardial ischemia reperfusion in adult SD rats and its possible mechanism.Methods:Forty Male SD rats were divided randomly into five groups(n=8).The myocardial injury of rats ware produced by the ligation of left coronary artery for 30 min followed by 120 min reperfusion.LVSP

LVEDP

and ±dp/dtmax were recorded at ischemia 30 min

reperfusion 60

90 and 120 min.The myocardial infarct size and the level of NO and NOS were observed.Results:In group I/R

the systolic and diastolic function were significantly reduced;myocardial infarct size was increased;NO and NOS were significantly lowered compared with those in group SH(P<0.05).The systolic and diastolic function were improved;myocardial infarct size was significantly smaller;the level of NO and NOS were increased significantly in group PU as compared with those in group I/R(P<0.05).All these parameters in group PU+LY were not improved compared with those in group PU(P<0.05).There was no significant difference among the parameters of groups PU+LY

I/R+LY

and I/R.Conclusion:Preconditioning with puerarin can significantly reduce myocardial ischemia-reperfusion injury

the mechanism of which is partly via PI3K-Akt signal transduction.