ABSTRACT
Objective To study the effect of erythropoietin（EPO） on PI3-K/Akt signal pathway of myocardial ischemia-reperfusion injury（I/R） in immature rabbits. Methods Thirty immature rabbits were randomly divided into two groups （n = 15/greup ）, The rabbits were intraperi- toneally injected with 2 ml of normal saline in control group, or 5 000 U/kg of EPO in treated group 24 h before I/R. The Langendorff isolat- ed perfused heart model was established, and the myocardial expression of PI3K, AKT and Caspase 9 were examined by immunohistochem- istry in 2 h after repeffusion. To monitor the myocardial apoptosis,we performed TUNEL in 2 h after reperfusion. Results The expression of myocardial PI3K and AKT in EPO group was significantly higher in EPO-treated group than those in control group. In EPO-treated group, the expression of myocardial caspase 9 was significantly lower than that in control group. The average optical density of myocardial PI3K, AKT and caspase 9 were significantly different between both groups （P 〈 0.01 ）.The number of apoptotic cell was significantly fewer in EPO- treated group than that in control group. The myocardial apoptosis index （AI）was significantly different between two groups （P 〈 0.01 ）. Conclusion EPO pretreatment can influence the PI3-K/Akt signal pathway and decrease the myocardial apoptosis,and significantly reduce the myocardial ischemia-reperfusion（I/R） injury in immature rabbits.