大鼠局灶性脑缺血血管内皮生长因子表达的研究

目的 研究血管内皮生长因子（vascular endothelial growth factor VEGF）在局灶性脑缺血中不同时相的表达，以探索血管内皮生长因子在局灶性脑缺血中的作用。方法 制作大鼠自体血栓性MCAO模型，在不同时点用免疫组化染色观察血管内皮生长因子表达情况。同时观察局灶性脑缺血后血管形成情况。结果 VEGF在局灶性脑缺血后6h表达增强。24h达高峰，在1周、2周恢复到对照水平。VEGF主要在缺血半暗带神经元、胶质细胞及血管内皮细胞表达；在缺血后48h半暗带周边出现血管增生，1周后达高峰。结论 在局灶性脑缺血早期VEGF在神经细胞、胶质细胞、血管内皮细胞等均有表达，可促进缺血半暗带的血管增生，对改善缺血半暗带血供有重要作用。

Investigation of Expression of Vascular Endothelial Growth Factor in Focal Cerebral Ischemia of the Rats

Objective To explore the expression of vascular endothelial growth factor at different time point after transient focal cerebral ischemia in order to understand the action of VEGF in ischmic brain. Methods The rats were subjected to embolic focal ischemia by placing homologous blood clots into the middle cerebral artery. The expressions of VEGF of all groups were analysed by immunohistochemistry at different time points after ischemia. Results Compared with the contralateral hemisphere,the expression of VEGF increased in the penumbra at 6h after MCAO and the highest expression occurred at 24 h after MCAO,followed by decreasing gradually to the normal level at 1 week. VEGF expressed mainly in neurons, glial cells and vascular endothelial cells in the penumbra. Angiogenesis was seen in the penumbra at 48 h after focal cerebral ischemia and reached the highest level at 1 week after ischemia. Conclusion VEGF expresses in neurons, glial cells and vascular endothelial cells at the early stage of focal cerebral ischemia. The expression speeds up the angiogenesis in the penumbra,improves blood provision and helps to recover nerve function.