Aim To investigate the role of cytokines in myocardium following coronary microembolization(CME) and the effects of ethyl pyruvate as a myocardial protective agent in the rat CME model. Methods We created a rat model of CME by injecting a suspension of autogenic microthrombotic particles into left ventricle.36 rats were randomly divided into 3 groups,each consisted of 12 rats: sham-operation group(SO),CME model group and ethyl pyruvate intervention group(EP).Haemodynamic measurements were performed on day 3 and then the rats were sacrificed. Protein expressions of tumor necrosis factor-alpha(TNF-α),interferon-1(IL-1β) were analyzed by Western blotting.Alterations of TNF-α,IL-1β mRNA were quantitatively assessed by Real-time PCR. Results Compared with the sham group, left ventricular systolic pressure(LVSP) and the maximum rise rate of left ventricular pressure(+dp/dtmax) significantly decreased(P<0.05),while left ventricular end diastolic pressure(LVEDP) significantly increased(P<0.05) in the CME group.Compared with those of the sham group,the expressions of TNF-α,IL-1β protein and gene were significantly increased in CME group(P<0.05). Ethyl pyruvate significantly suppressed protein and mRNA expression of TNF-α,IL-1β(P<0.05),improved cardiac functions. Conclusion In this study of rat after coronary microembolization,ethyl pyruvate preserved cardiac function due to supression of the TNF-α and IL-1β.