实验性局灶性脑缺血不同脑区VEGF、VEGFR-1、2表达及意义

Expressions and roles of VEGF, VEGFR-1,2 in different cerebral areas of experimental regional ischemic rats

目的 通过探索血管内皮生长因子及其受体在局灶性脑缺血中的表达 ,进而探求血管内皮生长因子在局灶性脑缺血中的作用。方法 应用左侧颈总动脉结扎加缺氧诱导的方法 ,建立 SD大鼠永久大脑中动脉闭塞模型 ,应用免疫组化方法检测血管内皮生长因子及其受体 (VEGF、VEGFR- 1、2 )的表达 ,同时观察局灶性脑缺血后血管型成情况。结果 VEGF及 VEGFR- 1、2在局灶性脑缺血后 6 h表达增强 ,2 4 h达高峰 ,在 1周、2周恢复到对照水平。 VEGF主要在缺血半影区 (IP)神经元、胶质细胞及血管内皮细胞表达 ;VEGFR- 1、2主要在缺血半影区血管内皮细胞表达。在缺血后 4 8h半影区周边出现血管增生 ,1周后达高峰。结论 在局灶性脑缺血早期 VEGF及VEGFR- 1、2在神经细胞、胶质细胞、血管内皮细胞等均有表达 ,可促进缺血半影区的血管增生 。

Objective To investigate the expression and role of VEGF and VEGFR 1,2 in the focal cerebral ischemia. Methods The model of middle cerebral artery occlusion was established with the suture occlued method under hypoxia induction.The expression of VEGF and VEGFR 1,2 was observed by immunohistochemistry in SD rats after different times of cerebral ischemia.Results Compared with the contralateral hemisphere,the espression of VEGF and VEGFR 1,2 increased in the penumbra at 6h after MCAO and the highest expression occurred at 24h after MCAO,then decreased gradually to the normal level at 1 week and 2 week respectively.VEGF expressed mainly in neurons,glial cells and vascular endothelial cells in the penumbra and VEGFR 1,2 appeared mainly in vascular endothelial cells of the penumbia. Angiogenesis was seen in the penumbra at 48h after focal cerebral ischemia and reached the highest level at week 1 after ischemia.Conclusion VEGF and VEGFR 1,2 express 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.