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.