大鼠局灶性脑缺血再灌注后促红细胞生成素蛋白表达的变化

The changes of erythropoietin expression in rat brain after cerebral ischemia and reperfusion injury and its biological significance

目的探讨大鼠局灶性脑缺血再灌注后脑组织促红细胞生成素（EPO）蛋白表达的变化。方法将SD雄性大鼠随机分为3组：正常组、假手术组和缺血再灌注组，缺血再灌注组大鼠采片j局灶性脑缺【0【再灌注模型。在缺血2h再灌注24、48、72和96h对大鼠进行神经功能缺火体征评分，采用免疫荧光标记法和WesternBlot法检测大鼠脑组织EPO蛋白表达的变化。结果与缺血阿灌注24h神经功能缺失体征评分（3．00±0．22）分相比较，随着大鼠脑缺血再灌注时间（48h、72h、96h）的延K，神经功能缺失体征评分越高[（3．40±0．32）分、（3．60±0．17）分、（3．70±0．21）分，均P〈0．051。免疫荧光标记法和WesternBlot法结果分别显示，大鼠局灶性脑缺血再灌注24hEPO蛋白开始出现表达（0．36±0．05、140．20±0．30），48h明显增多（1．09±0．10、145．40±0．16），72h达高峰（1．29±0．09、156．23±0．12），96h开始下降（0．98土0．04、141．56土0．36）。结论脑缺血再灌注损伤nI诱导EPO蛋白表达增强，提示EPO可能对神经细胞缺血缺氧损伤具有保护作蹦。

Objectives To investigate the changes of erythropoietin（EPO）expression in rats after focal cerebral ischemia/reperfusion injury. Methods Male Sprague-Dawley rats were randomly divided into normal, sham, cerebral ischernic/reperfusion（CIR）groups. Middle cerebral artery occlusion （MAC（）） model was established by I.onga＇s method, and reperfusion was followed 2 hours after occlusion in CIR group. The rats＇ brain neurological deficit scores were evaluated at 24 h,48 h,72 h and 96 h after reperfusion. The protein expression of EPO was determined by immunohistochemistry staining and Western blotting in each time points. Results The rats＇ brain neurological deficit scores at 48 h,72 h and 96 h were significantly increased（3.40±0.32,3.60±0. 17,3.70±0.21,all P 〈0.05）eompared with those at 24 h （ 3. 00 ± 0. 22 ） after reperfusion in CIR group. The results of immunohistochemistry staining and Western blotting showed that the positive expression of EPO proteins in rats started at 24 h（0. 36±0. 05,140. 20±0. 30）after cerebral ischemic/reperfusion injury, increased significantly at 48 h（ 1.09 ±0.10,145. 40 ± 0.16 ）, reached the peak at 72 h （ 1.29 ± 0.09, 156. 23±0. 12）,began to decline at 96 h（0.98±0.04,141.56±0.36）. Conclusions Cerebralischemia and reperfusion injury can induce increased expression of EPO protein, which suggests that EPO may have protective effect on nerve cells under the condition of ischemia and reperfusion.