毛冬青总黄酮提高大鼠脑缺血耐受作用研究

目的?观察毛冬青总黄酮对脑缺血预处理大鼠的保护作用及对皮层、海马CA1区脑源性神经营养因子(Brain-derived neurotrophic factor， BDNF)、胶质细胞源性神经营养因子(Glial-derived neurotrophic factor， GDNF)、血管内皮生长因子（Vascular endothelial growth factor， VEGF）蛋白表达的影响，探讨毛冬青总黄酮提高脑缺血耐受的作用机制。方法?采用阻断大鼠双侧颈总动脉血流10min做为脑缺血预处理(Cerebral ischemic preconditioning， CIP)模型，72h后阻塞大脑中动脉(Middle cerebral artery occlusion， MCAO)2h作为脑缺血再灌注模型。Wistar大鼠随机分为5组:假手术组（Sham），脑缺血再灌注损伤组（cerebral ischemia reperfusion， I/R），脑缺血预处理组（CIP+MCAO），毛冬青总黄酮高剂量组（IPTF，200mg/kg），毛冬青总黄酮低剂量组（IPTF，100mg/kg）。 采用神经缺损评分（NDS）法评价行为学改变，TTC染色法评价脑梗死体积，免疫组化法观察BDNF、GDNF、VEGF的表达变化。 结果?毛冬青总黄酮能明显改善脑缺血预处理大鼠神经功能缺损评分，减小脑梗死体积；增加皮层、海马CA1区BDNF、VEGF蛋白阳性表达面积和积分光密度值。结论?毛冬青总黄酮提高脑缺血耐受的作用与上调BDNF、VEGF内源性保护蛋白的表达有关。 

Effects of Ilex Pubescens Total Flavonoids on Improving Cerebral Ischemic Tolerence

OBJECTIVE?To observe the neuroprotective effects of ilex pubescens total flavonoids(IPTF) on the rats with cerebral ischemic preconditioning(CIP) and the expressions of BDNF， GDNF and VEGF in the cortex and hippocampus CA1 area， to explore the mechanisms of IPTF on improving cerebral ischemic tolerance. METHODS?CIP was performed by bilateral common carotid artery occlusion for 10min in rats. 72h later， cerebral ischemia reperfusion(I/R) was established by middle cerebral artery occlusion(MCAO) for 2h. Wistar rats were randomly devided into five groups， Sham group， I/R group， CIP+MCAO group， IPTF high dose group（200mg/kg） and IPTF low dose group（100mg/kg）。The behavioral injury was detected by neurologic deficit scores(NDS)， and the infarct areas were detected by TTC staining. The expressions of BDNF， GDNF and VEGF in cortex and hippocampus CA1 area were measured by immunohistochemical staining. RESULTS?IPTF decreased the neurologic deficit scores and the infarct areas. It also increased the positive area and integral optical density of BDNF， VEGF in cortex and CA1 area of rats with CIP. CONCLUSION?The mechanisms of IPTF on improving cerebral ischemic tolerance may be related with the up-regulation of the endogenous protein BDNF and VEGF.