大鼠脑缺血后海马CA1区胶质纤维酸性蛋白表达与迟发性神经元死亡的关系

目的观察大鼠大脑缺血再灌注后海马CA1区胶质纤维酸性蛋白(GFAP)的表达与迟发性神经元死亡的关系。方法采用大鼠大脑中动脉阻塞再灌注模型(MCAO),将大鼠随机分为MCAO后3d、7d、30d组及假手术组,应用免疫荧光与TUNEL染色法分别观察脑缺血再灌注后不同时间点缺血侧海马CA1区GFAP表达情况和迟发性神经元死亡(DND)的变化。结果(1)3d组海马DND阳性(DND 组)的MCAO大鼠、海马DND阴性(DND-组)的MCAO大鼠与假手术组大鼠比较,缺血侧海马CA1区GFAP染色的平均光密度无显著性差异(P>0.05),但GFAP阳性细胞的形态发生变化;(2)7d组大鼠缺血侧海马CA1区GFAP阳性细胞大量活化增殖,表现为胞体变大,突起增多;DND( )、DND(-)组海马CA1区GFAP染色的平均光密度较假手术组增高(P<0.01),且DND(-)组的GFAP平均光密度较DND( )组明显增高(P<0.01);(3)30d组大鼠缺血侧海马CA1区GFAP表达呈瘢痕样改变,DND( )、DND(-)组与假手术组比较其GFAP染色的平均光密度明显增高(P<0.05),且DND( )组的GFAP平均光密度较DND(-)组明显增高(P<0.05)。结论大鼠MCAO后星形胶质细胞反应性变化的差异可能与海马CA1区迟发性神经元死亡的发生有关。

The correlation of GFAP expression and delayed neuronal death in CA1 after ischemia-reperfusion of rat brain

Objective To observate the relations of glial fibrillary acidic protein(GFAP) expression and delayed neuronal death(DND) in hippocampal CA1 after ischemia -reperfusion of rat brain.Methods Rat middle cerebral artery occlusion reperfusion models(MCAO) were applied,and the animals were divided into 3 d Group,7 d group and 30 d group after MCAO and the sham group.The expression of GFAP and DND in hippocampal CA1 region was observed and analsized by immunofluorescence and TUNEL staining at different time points after cerebral ischemia.Results(1) 3 d group:in ischemic hippocampal CA1.average Optical density of GFAP immuno-staining of the DND positive(DND ) group and the DND negative(DND-) group,compared with the sham group,had no significant difference(P>0.05),but the GFAP positive cells showed morphological changes.(2) 7 d group:Cerebral ischemia side showed reactive gliosis with hypertrophic glial cells exhibiting prominent GFAP staining and long,thick processes.Average Optical density of DND( ) and DND(-) Group in hippocampal CA1 were much higher than sham group(P<0.01);and average optical density of DND(-) Group was significantly higher than the DND( )(P<0.01).(3)30 d Group:GFAP expression showed a scar-like change in ischemic rat hippocampal CA1,average Optical density of DND( ),and DND(-) group increased significantly(P<0.05) compared with the sham group.Conclusions The differences of astrocytic GFAP expression in hippocampal CA1 region after MCAO were correlation with the occurrence of the DND.