氨甲酰促红细胞生成素对缺血性脑损伤的保护作用

目的 探讨氨甲酰促红细胞生成素(CEPO)对缺血性脑损伤的保护作用及机制,并与促红细胞生成素(EPO)进行比较.方法 用腔内线栓法制造小鼠脑缺血再灌注动物模型;用蛋白免疫印迹法分析内皮型一氧化氮合酶(eNOS)和活化型caspase-3的变化;用免疫组织化学方法观察诱导型一氧化氮合酶(iNOS)的改变;用TUNEL法观察凋亡细胞.结果 脑缺血后大脑皮质eNOS、iNOS和活化型caspase-3表达显著上升;CEPO和EPO对eNOS表达无明显影响,但使活化型caspase-3表达从95.4%±16.7%明显下降至43.5%±13.1%(t=5.99,P<0.01),使缺血皮质iNOS表达从(3.1±1.9)细胞数/矩形区域下降至(0.7±0.2)细胞数/矩形区域(t=3.08,P<0.05);EPO使缺血皮质细胞凋亡数从对照组的(94.2±15.2)TUNEL(+)细胞数/矩形区域降至(40.5±9.8)TUNEL(+)细胞数/矩形区域(t=7.27,P<0.01),CEPO的抗细胞凋亡作用与EPO相同.结论 CEPO具有与EPO相同的抗细胞凋亡作用,它们通过减少活化型caspase-3和iNOS的表达而发挥神经保护作用.

The protection of carbamylated erythropoietin on focal ischemic brain injury

Objective To study the protection and its mechanism of carbamylated erythropoietin (CEPO) on ischemic brain injury and to compare its function with erythropoietin (EPO).Methods Focal cerebral ischemia/reperfusion was induced by occlusion of the middle cerebral artery (MCAO) using the intraluminal filament technique.The expression of endothelial NO synthase (eNOS) and activated caspase-3 were detected with Western blot.The inducible NO synthase (iNOS) positive cells were detected by immunohistochemistry staining.The apoptotic cell was detected by TUNEL staining.Results The expression of eNOS, iNOS and activated caspase-3 in cerebral cortex significantly increased after MCAO.The influence of CEPO and EPO on eNOS in ischemic cortex were not significantly different.However, the expression of activated caspase-3 markedly dropped from 95.4%±16.7% in group NS to 43.5%±13.1% in group CEPO and 45.1%±11.2% in group EPO (t=5.99 and 6.13,P<0.01).Immunohistochemistry staining revealed iNOS positive cells in ischemic cortex was (3.1±1.9) cells/square, CEPO and EPO remarkably reduced them to (0.7±0.2) cells/square and (0.8±0.2) cells/square, respectively (t=3.08 and 2.95, P < 0.05).The apoptotic cells in ischemic cortex fell from (94.2±15.2) cells/square in group NS to (40.5±9.8) cells/square in group CEPO (t=7.27, P < 0.01), the anti-apoptosis by EPO was similar to CEPO.Conclusion CEPO and EPO have the similar function of anti-apoptosis by inhibiting expression of activated caspase-3 and iNOS.