大鼠脑缺血再灌注后GFAPmRNA及其蛋白表达水平的变化

目的探讨胶质纤维酸性蛋白(GFAP)mRNA及其蛋白在大鼠脑缺血再灌注损伤过程中表达水平的变化.方法采用大脑中动脉阻断法制作缺血再灌注模型,应用RT-PCR和免疫组织化学方法观察大鼠大脑中动脉阻塞再灌注后3、7、30d损伤侧皮层星型胶质细胞GFAP mRNA及其蛋白的表达.结果再灌注后3d,手术组GFAP mRNA表达水平较假手术组明显增高(P＜0.01);再灌注后7d,GFAP mRNA和其蛋白表达水平均明显增高(均P＜0.01);再灌注后30d,GFAPmRNA恢复到正常水平,梗死灶边缘胶质疤痕形成.结论大鼠大脑中动脉缺血后可引起其皮层损伤侧星形胶质细胞持续分化、增殖,但星形胶质细胞在中枢神经系统损伤后早期作出的抗损伤反应及修复机制与损伤后期发生的病理生理机制可能有很大的差别.

Alterations in expression of GFAPmRNA and correlated protein after cerebral ischemia/reperfusion in rats

Objective To investigate the changes of glial fiber acid protein(GFAP) and GFAPmRNA levels after brain ischemia/reperfusion injury in rats. Methods Focal cerebral ischemia was induced by occlusion of middle cerebral artery (MCAO) for 60min and followed reperfusion. Subsequently the levels of GFAPmRNA and correlated protein in ischemic cortex at different time were determined by RT-PCR and immunohistochemistry. Results The expression of GFAPmRNA was markedly increased 3d after reperfusion, while the correlated protein significantly increased by d7. After 30 d of reperfusion the levels of GFAPmRNA decreased to normal with the formation of colloid scar in the margin of ischemic core. Conclusion This study demonstrates that focal cerebral ischemia in rat results in continual response, a process often referred to as reactive astrogliosis, but astrocytes may play different roles in the pathophysiological process at different stage.