重组人红细胞生成素对大鼠心肌梗死的治疗作用

目的　观察重组人红细胞生成素 (rHu EPO)治疗心肌梗死大鼠心功能和心肌细胞凋亡情况 ,探讨其机制。方法　 3 2只SD大鼠分空白组 (Sham )、心肌梗死组 (MI)和治疗组 (MI EPO) ,结扎左冠前降支制备心肌梗死的模型 ,治疗组每天腹腔注射 5 0 0 0IU /kg体重rHu EPO共 7d ,14d后所有大鼠检测血流动力学指标 ,心脏切片原位末端标记 (TUNEL)检测凋亡 ,免疫组织化学检测bcl 2、bax表达。结果　心肌梗死组凋亡指数 (AI)为 1.65 % ,bcl 2及bax蛋白阳性表达指数 (PEI)分别为 0 .96%和 1.3 4% ,均明显高于空白组 (P <0 .0 5 ) ;治疗组心功能保存较好 ,AI与bax蛋白PEI分别为 0 .84%和 0 .68% ,均下降 (P <0 .0 5 ) ,而bcl 2蛋白PEI增高 (P <0 .0 5 )为 1.43 %。结论　rHu EPO可抑制心肌细胞凋亡 ,保存心功能。可能是通过下调bax表达和上调bcl 表达实现的。

An experimental study of recombinant human erythropoietin in the treatment of acute myocardial infarction in rats

Objective To observe the changes of myocardial function and apoptosis in the acute myocardial infarction SD rats treated with recombinant human erythropoietin (rHu-EPO) and study the mechanisms.Methods Thirty two rats were divided into three groups: sham operation group (Sham),acute myocardial infarction group (MI) and treated group (MI EPO).Acute myocardial infarction model was made by ligating the anterior descending coronary artery.rHu-EPO was administered i.p.in MI EPO group at the dose of 5 000 U/kg body weight immediately after the ligation.Each animal in MI EPO group received the same dose of rHu-EPO daily the next six days.At the 14th day all animals underwent hemodynamic measurements and then executed,the samples were examined by using hematoxylin and eosin (HE) stain,immunohistochemistry technique (bcl-2,bax) and TdT-mediated dUTP nick end labeling (TUNEL) dyeing.Results Hemodynamic function of the rats in MI EPO group was much better than that in MI group.The ratio of the positive cells for TUNEL and bax in MI EPO group were lower than that in MI group (0.84% vs 1.65%,0.68% vs 1.34%,respectively).The ratio of the positive cells for bcl-2 in MI EPO group was higher than that in MI group (1.43% vs 0.96%).Conclusion These findings suggested that rHu-EPO could improve myocardial infarction by attenuating apoptosis.Potential mechanism is to up-regulate the bcl-2 expression and down-regulate the bax expression.