缺血再灌注后脑细胞凋亡和Caspase-3蛋白的表达

目的：观察大鼠局灶性脑缺血再灌注后细胞凋亡及分子机制。方法：雄性SD大鼠，采用可逆性大脑中动脉内线栓法建立局灶性脑缺血再灌注模型。于缺血不同断头取脑，采用免疫组织化学检测Caspase-3蛋白表达，HE染色，甲苯胺蓝染色，光镜检查细胞损伤改变，测定丙二醛（MDA）含量。结果：光镜检查发现，缺血1h未见明显的神经细胞坏死；缺血2h,3h,6h组，出现细胞坏死及凋亡改变，假手术组未见上述变化；随缺血时间的延长Caspase-3蛋白表达呈递增趋势，Caspase-3蛋白表达时相与神经细胞的凋亡基本一致；缺血再灌注2h组比缺血再灌注0.5h组MDA含量明显增加。结论：随缺血及再灌注时间延长脑损伤逐渐加重，缺血性卒中溶栓治疗应在缺血1h以内进行，Caspase-3蛋白表达增加是引起细胞凋亡的分子机制之一。

Cell apoptosis and its relation to the expression of Caspase-3 protein after focal cerebral ischemia-reperfusion in rats

Aim:To study the cell apoptosis and its molecular mechanism for focal cerebral ischemia reperfusion model rats.Methods:The model of focal cerebral ischemia reperfusion was established with the suture occluded method.Caspase 3 protein in rats at different time polits of cerebral ischemia reperfusion was observed by immunohistochemical method,the cell structure was examined under light microscope,and the content of MDA was measured. Results:There was no significant cell necrosis in 1 h ischemia reperfusion group.There was significant cell necrosis and apoptosis in 2 h, 3 h,and 6 h ischemia reperfusion groups, but there was no injury in sham operation group. The level of Caspase 3 protein in 6 h ischemia reperfusion group was significantly higher than those of other groups. The time phase pattern of Caspase 3 protein was consistent with that of cell apoptosis. The content of MDA was significantly higher in 2 h ischemia reperfusion group than in that of 0.5 h ischemia reperfusion groups. Conclusion:The injury of neuronal cell aggravates with the ischemia reperfusion time;treatment within 1 h after ischemia is effective,and the increase of Caspase protein would be one of the molecular mechanisms of cell apoptosis in ischemia reperfusion.