Effects of Ethyl Pyruvate on Myocardial Apoptosis and Expression of Bcl-2 and Bax Proteins after Ischemia-reperfusion in Rats

In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion(I/R) in vitro and the expression of Bcl-2 and Bax proteins,isolated rat hearts were perfused in a Langendorff model.Twenty-four rats were randomly divided into 3 groups(n=8 in each group):control group was perfused for 120 min.In the I/R group,after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion.Ethyl pyruvate(EP) group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 min before ischemia and throughout reperfusion.Myocardial malonaldehyde(MDA) content was measured.Myocardial apoptotic index(AI) was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL) method.The expression of antiapoptotic protein Bcl-2 and proapoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry.As compared with control group,the content of MDA,myocardial AI and the expression of Bcl-2,Bax proteins were increased significantly in I/R group,but the content of MDA,myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group(P<0.05).These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress,up-regulating Bcl-2 and down-regulating Bax proteins.