大鼠创伤性颅脑损伤后EPO及受体的表达与意义

目的观察创伤性颅脑损伤大鼠皮层中促红细胞生成素（EPO）及其受体（EPOR）的分布与表达变化，并探讨其意义。方法35只雄性Wistar大鼠，随机分为正常对照组和颅脑损伤后2h、6h、12h、24h、3d和7d共7组，每组各5只。采用Myneurolab脑立体定向仪和Benchmark颅脑损伤撞击器制作创伤性颅脑损伤模型。应用免疫组化和Westernblot分别检测上述时间点损伤灶周围皮层中EPO及EPOR的蛋白表达变化。结果EPO与EPOR广泛表达于神经元、少突胶质细胞和血管内皮细胞中。EPO与EPOR在创伤性颅脑损伤后2h即可见表达增强，6～12h表达继续升高，至24h达高峰，随后EPO的表达开始减弱，而EPOR的表达在24h后持续维持在高水平，无明显降低。结论创伤性颅脑损伤后EPO与EPOR的表达随时间变化不一致。EPOR的持续高水平表达是外源性EPO发挥神经保护作用的分子基础。

Expression of erythropoietin and its receptor in cerebral cortex after traumatic brain injury in rats

Objective To investigate the expression and significance of erythropoictin （EPO） and erythropoietin receptor （EPOR） in a rat model of traumatic brain injury （TBI）. Methods Thirty-five male Wistar rats were randomly divided into two groups： the control group （n =5） and the TBI group （n =30）. TBI group was sub-divided into 6 groups according to the time elapsed post injury （2 h, 6 h, 12 h, 24 h, 3 d and 7 d after TBI）. The TBI models were produced by Myneurolab Stereotaxic Apparatus （ U. S. A. ） and Benchmark Stereotaxic Impactor （ U. S. A. ）. Animals were sacrificed and their cerebral cortices inclusive of the TBI site were harvested at the indicated time point. Subsequently, EPO and EPOR expressions were detected by mmmohistochemical staining and Western blot. Results The EPO and EPOR immunoreactivity were generally found in neurons, oligodendrocytes and vascular endothelial cells. Immunohistochemical staining and Western blot revealed that the expression of EPO and EPOR started to increase at 2 h after Till, which continued to rise at 6 h and 12 h, and reached a peak at 24 h. After 24 h, the expression of EPO gradually decreased while the expres- sion of EPOR maintained the high level until 7 d after TBI. Conclusion There are different changes in the ex- pression of EPO and EPOR after TBI. Continuous high expression of El＇OR provides a molecular basis for the neuroprotection of exogenous EPO.