外源性bFGF对新生大鼠脑GFAP蛋白表达影响的动态研究

目的: 探讨缺氧缺血对新生大鼠脑星形胶质细胞酸性蛋白(GFAP)和内源性碱性成纤维细胞生长因子(bFGF)的作用以及外源性bFGF对缺氧缺血后GFAP表达的影响.方法:采用免疫组化染色方法观察GFAP表达强度的变化.结果:生后7 d时正常新生鼠脑内有微弱GFAP表达.生后14 d,GFAP阳性细胞数量及染色强度呈高峰状态,主要见于脑白质区.生后28 d海马、脑白质内有少量GFAP阳性细胞.缺氧缺血后GFAP表达增加,以缺氧缺血后48 h明显.外源性bFGF增加GFAP的表达,以用药后24 h作用明显,并持续至用药后5 d.正常新生鼠脑有一定程度的内源性bFGF表达,生后10 d表达呈高峰状态.以后一直有少量bFGF表达,其组织学分布与GFAP大致相似.结论:缺氧缺血可诱导内源性bFGF及GFAP的表达.外源性bFGF可增强缺氧缺血时新生鼠脑GFAP的表达,补充内源性bFGF的不足,在缺氧缺血时神经元损伤修复中发挥一定保护作用.

Effects of exogenous bFGF on glial fibrillary acidic protein expression in neonatal rat brain with hypoxic-ischemic brain damage

Objective: To investigate the effect of hy po xia-ischemia on glial fibrillary acidic protein (GFAP) and endogenous basic fib roblast growth factor (bFGF), and the effect of exogenous bFGF on GFAP expressio n in hypoxic-ischemic brain of neonatal rats. Methods: Expres sions of GFAP and endogenous bFGF were examined with immunohistochemical stainin g and image quantitative analysis. Results: Expression of GFAPwas weak in rats 7 days after birth and reached peak 14 days after birth, and w as major in cerebral white matter. The expression of GFAP was also detected in t he hippocampus and cerebral white matter 28 days after birth. The expression ofGFAP increased after hypoxia-ischemia and reached peak 48 hours after hypoxia- ischemia. Exogenous bFGF enhanced the expression of GFAP, and the effect was themost 24 hours after bFGF delivery and persistent to 5 days. Endogenous bFGF cou ld be detected in the brain of normal neonatal rats, which was most abundantly e xpressed 10 days after birth. Distribution of bFGF was similar to that of GFAP.Conclusion: Exogenous bFGF could enhance expression of GFAP inhypoxic-ischemic brain of neonatal rat, which may play important roles in rest oration of neurons damaged by hypoxia-ischemia.