促红细胞生成素在大鼠脊髓缺血再灌注损伤中的表达及其意义

目的:观察促红细胞生成素(EPO)在大鼠脊髓缺血再灌注损伤(SCII)中的表达和重组人促红细胞生成素(rhuEPO)预处理对再灌注损伤脊髓神经细胞的作用。方法:将W ister大鼠分为正常组、假手术组、rhuEPO处理组和生理盐水对照组;rhuEPO处理组和生理盐水对照组于术前3h腹腔注射rhuEPO和生理盐水,制备大鼠脊髓缺血再灌注损伤模型。以免疫组化和W estern blot法检测脊髓组织中EPO的表达变化;以原位末端脱氧核糖核苷酸转移酶介导dUTP标记法(TUNEL法)检测细胞的凋亡情况。结果:EPO在无损伤脊髓中即有少量的表达,SCII后8h表达显著上调,于12、24h(12h与24h组比较差异无显著性意义,P>0.05)达高峰,伤后3d表达逐渐下调,5d仍保持较高水平。rhuEPO处理组SCII后8h、12h及24h时神经细胞凋亡水平明显低于生理盐水对照组,差异有显著性意义(P<0.01)。结论:在脊髓缺血再灌注损伤中EPO呈现时序性表达变化,可能是机体内源性神经保护的机制之一;EPO预处理能明显抑制SCII后神经细胞的凋亡。

Expression and role of erythropoietin on the spinal cord ischemic reperfusion injury in adult rats

Objective:To investigate the expression of erythropoietin(EPO) on spinal cord ischemic reperfusion injury(SCII) in rats,and the neuroprotection role of recombinant human erythropoietin(rhuEPO) administered before SCI.Method:Male rats were randomized into normal group,sham operation group,normal saline group and erythropoietin group.At 3 hours before SCI,saline and rhuEPO was injected into the abdominal cavity.The expression changes of EPO in spinal cord were detected through the adoption of western blot and immunohistochemistry,and the neural cells apoptosis was detected through the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) methods.Result:The expression of EPO was detected in non-injuryed spinal cord,significantly increased at 8h and peaked at 12,24h after SCI,but appeared to decline after reperfusion on 3rdd,and remained significantly higher than that of the non-injured spinal cord after reperfusion on 5thd.RhuEPO significantly reduced the neural cells apoptosis in the injuried spinal cord in comparison with that of control animal receiving saline at 8,12,24h after SCI(P<0.01).Conclusion:EPO was induced by SCI in rats,and changed in a time-depend maner,it may be one of endogenous nerve protective mechanisms.The administration of rhEPO significantly reduces the apoptosis of neural cells after SCI.