大鼠脑缺血时碱性成纤维细胞生长因子表达的变化

目的:观察局灶性脑缺血时,大鼠脑内碱性成纤维细胞生长因子(bFGF)表达分布的改变。方法:用荧光免疫组化方法观察bFGF的表达。用MCAO模型造成大鼠局灶性脑缺血损伤。结果:缺血后,bFGF在纹状体及额顶叶皮质均显著升高。在纹状体梗塞核心及周边区,bFGF主要在星状胶质细胞内表达;在邻近梗塞的区域,bFGF灰度比率从98％±10％增至125％±6％,神经元内也少量表达。在额顶叶皮质,bFGF灰度比率从104％±11％增至132％±28％。bFGF主要分布于神经元内。结论:局灶性缺血大鼠脑内不同区域bFGF表达的增加有所差异,提示纹状体内,可能主要由星状胶质细胞起神经保护作用;而在皮质,可能由神经元起自我保护作用。

Alteration of basic fibroblast growth factor expression in rat during cerebral ischemia

AIM: To investigate the distribution and expression changes of basic fibroblast growth factor (bFGF)-like immunoreactivity (IR) in focal cerebral ischemic rat brain. METHODS: The expression of bFGF was observed by fluoro-immunohistochemistry. The focal cerebral ischemic injury was carried out using middle cerebral artery occlusion (MCAO) model. RESULTS: Confocal images demonstrated that both the striatum and the frontoparietal cortex showed increases of bFGF-like IR after 2-h MCAO and 24-h reperfusion. In striatum, the increase patterns of bFGF-like IR were different according to the ischemic extent. In the core of infarct and its surrounding region (with more IR induction), bFGF-like IR was mainly located in astrocytes. In region adjacent to infarct (with most IR induction, the grey ratio of bFGF-like IR increased from sham-98% +/- 10% to ischemia-125% +/- 6%), some neurons also showed an upregulation of bFGF-like IR. In frontoparietal cortex, strong induction of bFGF-like IR was mostly seen in neurons (The grey ratio of bFGF-like IR increased from sham-104% +/- 11% to ischemia-132% +/- 28%), although it was observed in astrocytes as well. CONCLUSION: The expression of bFGF increased after focal cerebral ischemia in rats, suggesting that: in striatum, astrocytes may play an important role in the protection of neurons via the overexpression of bFGF; whereas in cortex, neurons probably exert an autoprotection through expressing bFGF themselves.