Effects of erythropoietin on myocardial ischemia-reperfusion injury in rats

Objective: To explore the effects of erythropoietin on myocardial ischemia- reperfusion injury in rats. Methods: The left anterior descending coronary artery was ligated for 30 minutes and then loosed for 120 minutes to establish the rat model of myocardial ischemia-reperfusion injury. 50 SD rats were randomly divided into five groups: sham-operation,ischemia-reperfusion,EPO 100 U/kg,EPO 1000 U /kg and EPO 5000 U/kg. During the processes, lead Ⅱ ECG was traced continuously to note the arrhythmia caused by reperfusion;the levels of serum creatine phosphokinase isoenzyme (CK-MB),myocardial malonaldehyole (MDA) 、superoxide dismutase (SOD)、glutathione peroxidase ( GSH-PX)、catalase (CAT)、Na + -K +-ATPase and Ca 2+-ATPase were detected at reperfusion 120 min. And the changes of myocardial ultrastructures were observed. Results: Erythropoietin significantly reduced the incident of ventricle arrhythmia caused by reperfusion;reduced serum CK-MB and myocardial MDA content ,enhanced the activity of myocardial GSH-PX,CAT Na +-K +-ATPase,Ca 2+-ATPase at reperfusion 120 min; markedly attenuated injury of the myocardial ultrastructures caused by the ischemia- reperfusion. Erythropoietin did not change the activity of myocardial SOD. Conclusion: Erythropoietin has protective effects on myocardial ischemia- reperfusion injury in rats,and the mechanism may be related to relieving the injury caused by oxygen free radical and calcium overload.