VEGF在大鼠局灶性脑缺血再灌注损伤中的表达变化

目的 研究局灶性脑缺血再灌注中心区、半影区VEGF表达的动态变化及意义．方法 采用线检法制备大鼠局灶性脑缺血再灌注模型．采用神经病学评分、TTC染色、光镜检测对模型予以评价．在此基础上采用免疫组化技术，观察缺血3h及缺血3h再灌注3，6，24，72h缺血中心区及半影区VEGF表达的动态变化，以及观察相应时间点缺血中心区及半影区病理组织学变化．结果 正常对照组及假手术组VEGF呈阳性表达，缺血3h及缺血3h再灌注3，6h中心区及半影区VEGF表达明显增强，缺血3h再灌注24，72h缺血中心区VEGF表达接近正常，而此时半影区呈升高趋势，24h达到高峰，72h有所下降(与假手术组相比，P＜0．05)．相应神经元的病理组织学变化也随再灌注时间的延长而加重．结论 正常脑组织中VEGF呈弱阳性表达，缺血半影区随缺血再灌注时间延长表达增强．随着缺血再灌注时间延长，中心区神经细胞以坏死为主，半影区以神经细胞以凋亡为主．提示VEGF对脑缺血损伤后的神经细胞有保护和修复作用．

Changes of VEGF on Focal Cerebral Ischemia and Reperfusion in Rats

Objective To study the expression of VEGF during reperfusion after focal cerebral ischemia in rats.Methods The left middle cerebral arteries were transiently occluded by inserting a nylon thread into the carotid artery, used neurological scale, TTC stain, Pathohistology method to evaluate the model. On the basis of this, we used immunohistochemistry method to observe ischemic core and penumbra after 3?h of ischemia and at 3, 6, 24, 72?h of reperfusion after 3?h of ischemia.Results The expression of VEGF is slightly positive in control and sham operated group. The expression of VEGF increases obviously in ischemic core and penumbra after 3?h of ischemia and at 3, 6?h of reperfusion after 3?h of ischemia. It has great difference compared with the sham operated group. With the elongation of the time of reperfusion after ischemia in ischemic core expression of VEGF is nearly normal. While the expression of VEGF increases gradually. It reaches peak at 24?h, while it decreases at 72?h of reperfusion.Conclusion The expression of VEGF is at low levels in normal brain tissue with the elongation of ischemic time, the expression of VEGF increase gradually in penumbra. The nerve cells in ischemic core become necrotic with the elongation of reperfusion time after ischemia and the ischemia of neurons in penumbra become more apparent. Indicating that VEGF can protect and repair the nerve cells that have damaged after focal erebral ischemic and reperfusion in rats.