Protective effect of erythropoietin on myocardial ischemia/reperfusion injury in rabbits

Objective To investigate the influence of Erythropoietin on cardiac myocyte apoptosis and CK-MB level in myocardial ischemia/reperfusion(I/R)injury of rabbit,and to explore the protective effects of Erythropoietin and its mechanisms.Methods Sixteen New Zealand rabbits were randomly divided into two groups:I/R injury group(C)and Erythropoietin group(EPO group).Rabbits were subjected to descending coronary artery(LAD)occlusion to establish rabbit myocardial I/R injury models.When the LAD was ligated,recombinant human Erythropoietin(rhEPO)was injected in EPO group by ear vein,I/R group were injected saline equivalently.Observinvg indexs:(1)testing the serum concentration of CK-MB at 5 min before occlusion,60 min after occlusion,60 min and 180 min after reperfusion.(2)testing the apoptotic index of the corresponding ischemic myocardium myocardial cell at 180 min after reperfusion,observing the general myocardial tissue morphosis organizational structure by light microscope.Results The serum CK-MB concentration increased gradually with the ischemia and reperfusion time(P0.01).Before ischemia,the serum CK-MB concentrations had no significant difference between EPO group and the I/R group(P0.05).The CK-MB concentrations in EPO group were markedly lower comparing with the I/RI group at 60 min after ischemia,60 min and 180 min after reperfusion(all P0.01).Compared with the I/R group,the apoptotic index of ischemic zone in EPO group decreased significantly(P0.01).Conclusions EPO has clear protective effects on the myocardial I/R injury in rabbits.The mechanisms of its cardioprotection may be associated with stabilizing the myocardium cell membrane structure to decrease the release of myocardial enzyme and to inhibit cardiac myocyte apoptosis.