羟基红花黄色素A对局灶性脑缺血再灌注大鼠血管内皮生长因子表达的影响

目的 探讨羟基红花黄色素A对局灶性脑缺血大鼠血管内皮生长因子(VEGF)表达的影响及意义.方法 采用大鼠大脑中动脉闭塞(MCAO)模型,用免疫组化的方法观察HSYA对MCAO2 h及再灌注1、3、 6、 9、12、24、72 h及7 d、14 d时脑组织VEGF表达变化,并与对照组比较.结果 缺血2 h后VEGF在缺血灶周围小血管内皮细胞、神经细胞、胶质细胞上表达开始增高,内皮细胞在再灌注24～72 h时表达量最高,7 d后开始下降,14 d时仍偏高.神经细胞及胶质细胞在再灌注9～12 h时表达量最高,24～72 h时开始下降,7 d时已无表达.HSYA使各时间点VEGF的表达增加,并使缺血后期血管内皮生长因子表达的下降减缓.结论 HSYA具有上调脑缺血后血管内皮生长因子表达的作用,这可能是其脑保护作用的机制之一.

Effects of hydrosafflow yellow A on the expression of VEGF in rats with focal cerebral iscbemia reperfusion

Objective To investigate effect and significance of hydrosamow yellow A (HSYA) on the expression of vascular endothelial growth factor (VEGF) in rats with focal cerebral ischemia reperfusion.Methods With the application of the MCAO (middle cerebral artery occlusion) model, effects of HSYA on the changes in VEGF expression in rats were observed following 2 hours cerebral artery occlusion and ischemia -reperfusion at 1, 3, 6, 9, 12, 24, 72 hours and also at 7 and 14 days by using immunohistochemistry staining. Results VEGF expression in endothelia, neuron and gliocyte in the small vessels around ischemic foci increased at 2-3 h following ischemia. The expression of VEGF in endothelia reached a maximum at 24-72 h following reperfusion, then decreased 7 days later, but was still above normal level at week 2. The expression of neuron and gliocyte reached a maximum at 9-12 h after reperfusion, then decreased at 24-72 h, and no expression could be seen at week 1. HSYA could significantly enhance the expression of VEGF at all time points and decrease in the expression of VEGF could be seen at the late stage of ischemia. Conclusions HSYA could enhance the expression of VEGF following cerebral ischemia, which might be one of mechanisms of its protective effect on the brain system.