Objective:To investigate the effect of ischemic reperfusion(I-R) on the expression of Monocyte chemoattractant protein-1(MCP-1)and heme oxygenase-1 protein(HO-1) and mRNA of myocardial tissue and the protective role of erythropoi- etin (EPO). Methods:Ischemic reperfusion rat model was established in the experiments.24 animals were randomly divided into sham operation(F)

I-R group(O)and EPO group(E)and subjected to 45 min of myocardial ischemia by ligation of left anteri- or descending coronary artery followed by 180 min of reperfusion.The animals in EPO group were intraperitoneal by injec- tioned with EPO(4 000 U/Kg)24 hours before the operation. The expression of MCP-1 and HO-1 protein and mRNA was de- termined by immunohistochemistry and RT-PCR. Results:Campared with F group

the expression of myocardial MCP-1 and HO-1 protein and mRNA increased significantly in O group and E group (P<0.01);The expression of MCP-1 protein and mRNA was significantly higher in E group than that in O group(P<0.05);The expression of HO-1 protein and mRNA was significantly higher in O group than that in E group(P<0.01 and P<0.05). Conclusion:The pretreatment of EPO could protect cardiomyocyte against IRI through upregulating HO-1 expression and downregulating MCP-1.