大鼠闭合性脑损伤后星形胶质细胞的形态及GAP-43、ET-1 mRNA表达的变化

Changes of structure of astrocyte and expression of GAP-43 mRNA,endothelin-1 mRNA after closed diffuse brain lesion in rats

目的：探讨闭合性脑损伤后脑组织星形胶质细胞（Ast）形态学变化和生长相关蛋白（GAP-43）、内皮素-1（ET-1）mRNA表达的变化。方法：78只大鼠随机分为12个损伤组和1个假损伤对照组，每组6只。损伤组制备Marmarou脑损伤模型。各组分别于伤后0h、0．5h、1h、1．5h、2h、6h、12h、36h、48h、60h、66h、72h断头取脑，在脑干损伤灶周围取部分脑组织，常规固定切片HE染色，胶质纤维酸性蛋白免疫组化染色结合计算机彩色图像分析技术观察分析Ast形态，RT-PCR法检测GAP-43及ET-1 mRNA。结果：闭合性脑损伤后0．5hAst反应性肿胀最明显，以后随着时间的延长Ast反应性肿胀程度降低、肿胀Ast的数目减少。伤后6—72h脑组织GAP-43mRNA及ET-1mRNA均较假损伤对照组增高（P〈0．01）。结论：GAP-43及ET-1在脑损伤后血脑屏障损害的病理生理过程中起重要作用。

Aim ： To investigate the changes of structure of astrocyte and the expression of GAP-43 mRNA,endothlin-1 （ET-1）mRNA after diffuse brain lesion. Methods： The model of closed diffuse brain lesion was made. The brain tissue was prepared at different time points after brain lesion and the pathological changes of astrocytes were studied by HE staining,GFAP immuno-histochemical staining and image analysis, and the sham injury group was used as control. At the same time,the expressions of GAP-43 mRNA and ET-1 mRNA in brain stem tissue were measured by RT-PCR after diffuse brain lesion. Results： The swelling and proliferation of astrocytes were early observed after diffuse brain leison. The degree of astrocytic swelling was gradually declined with time. The expression of GAP-43 mRNA and ET-1 mRNA was higher in brain tissue during 6 - 72 h after diffuse brain lesion compared with sham injury group （ P 〈 0.01 ）. Conclusion ： GAP-43 and ET-1 play important roles in the pathophysiological process of blood brain barrier damage after diffuse brain lesion.