糖尿病大鼠局灶性脑缺血再灌注损伤中星形胶质细胞的变化

Alterations in Expression of GFAP after Cerebral Ischemia Reperfusion in Rats

目的探讨高血糖脑缺血再灌注损伤中星形胶质细胞的变化特点。方法采用链脲佐菌素制备1型糖尿病高血糖SD大鼠模型,通过大脑中动脉缺血模型(middle cerebral artery occlusion,MCAO)建立局灶性脑缺血再灌注模型,使用组织学、组织化学、免疫荧光及Western blot方法,对比观察糖尿病高血糖脑缺血再灌注组(简称高血糖组)与正常血糖脑缺血再灌注组(简称正常血糖组)在脑缺血2h后再灌注24h和48h大脑皮质区神经元细胞、星形胶质细胞组织学变化和胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达。结果正常血糖组再灌注24h脑组织出现轻度水肿;再灌注48h脑水肿加重,出现神经元固缩;高血糖组再灌注24h,较病变正常血糖组明显,再灌注48h脑水肿加重,固缩神经元进一步增加。正常血糖组缺血再灌注24h后,GFAP阳性细胞数量稍有增加;再灌注48h后,星形胶质细胞数量开始增多。高血糖组缺血再灌注24h和48h后,星形胶质细胞数目较同期正常血糖组增加(P<0.05),胞体显著增大,突起增粗、不均匀。脑组织Western blot结果可见,高血糖组GFAP的表达高于正常血糖组。结论糖尿病高血糖脑缺血再灌注能够加重神经元损伤,GFAP的表达增强,星形胶质细胞数量明显增加。

Objective To investigate the changing rule of astrocyte in hyperglycosemia cerebral ischemia reperfusion injury by observing the expression change of glial fibrillary acidic protein(GFAP) in hyperglycosemia cerebral ischemia reperfusion injury of rats.Methods Type I diabetes hyperglycosemia rat model was established Using streptozotocin.Through middle cerebral artery occlusion(MCAO),diabetes hyperglycosemia cerebral ischemia reperfusion injury mode in rat 1 was established.Applying histology,histochemistry, immunofluorescence and western blot,the histology change of the neuron of cerebral cortex of frontal lobe and astrocyte,the expression of GFAP of diabetes hyperglycosemia cerebral ischemia reperfusion group(hyperglycosemia group) and normoglycemia cerebral ischemia reperfusion group(normoglycemia group ) at 2 hours after cerebral ischemia,24hours and 48 hours after reperfusion were observed and compared.Results Gently edema occurred after reperfusion for 24 hours,edema was aggravated after reperfusion for 48 hours, and neuron was pyknosis in normoglycemia group.The pathology change was more obvious in diabetes group than that in the normoglycemia group after reperfusion for 24 hours.Cerebral edema was aggravated significantly and the number of pyknosis neuron were increased significantly after reperfusion for 48 hours.The number of positive cells increased a few after reperfusion for 24 hours and astrocyte was increased after reperfusion for 48 hours in normoglycemia group.The number of astrocyte was increased significantly after reperfusion for 24 hours and 48 hours in hyperglycosemia group than that in normoglycemia group(P &lt;0.05).The cell body became bigger obviously,cell process was lengthen and thicken inequable in hyperglycosemia group.Western blot showed that the expression of GFAP was significandy higher in diabetes group than that in normoglycemia group.Conclusion Diabetes hyperglycosemia cerebral ischemia reperfusion can aggravate neuron damage, reinforce the expression of GFAP and increase the number of astrocyte.