神经生长因子对大鼠缺血性脑损伤急性期的疗效研究

摘要

Objective: To evaluate the effect of nerve growth factor (NGF) on the cerebral ultrastructure and expression of synaptophysin (Syp) in rats with focal cerebral ischemia. Methods: Thirty-six healthy male SD rats were randomly divided into sham group (n= 12), ischemia group (n=12) and ischemia plus NGF group (n=12). Middle cerebral artery occlusion (MCAO)was generated by inserting a nylon thread with rounded tip at bifurcation of the right common carotid artery into the internal carotid artery. Rats in ischemia plus NGF group were treated with NGF (0.25 g/100 g, intraperitoneal injection) once a day for 14 days and rats in the other two groups were treated with normal saline solution once a day for 14 days. The expression of Syp was measured by western blot at day 14 after the operation and the cerebral ultrastructure was observed by electron microscopy at day 28 after the operation. Results: At day 14 after operation, the expression of Syp in the rats in ischemia and ischemia plus NGF group were significantly increased than that in sham group (P＜0. 01). The Syp expression in the rats in ischemia plus NGF group was higher than that in the ischemia group (P＜0.05). At day 28 after operation, the brain ultrastructural damage of brain in the rats in ischemia plus NGF group was less severe and more synapses with normal morphology were detected. Conclusion: In the acute stage of cerebral ischemia, intraperitoneal injection of NGF can reduce the ischemic injury in the rat brain, possibly by up-regulating the expression of Syp.%目的:观察神经生长因子(NGF)对脑缺血急性期大鼠脑组织超微结构及突触素(Syp)表达的影响.方法:健康雄性SD大鼠36只,随机分为假手术组、缺血组和NGF组各12只,后2组线栓法制备MCAO模型,NGF组给予NGF腹腔注射治疗14 d,其余2组腹腔注射等量生理盐水治疗14 d.术后14 d,Western Blot测定各组脑组织中Syp的表达;术后28 d,透射电镜观察各组脑组织超微结构.结果:术后14 d,缺血组和NGF组脑组织Syp蛋白含量均显著高于假手术组(P＜0.01),NGF组脑组织Syp蛋白含量高于缺血组(P＜0.05);术后28 d,电镜显示NGF组脑组织超微结构损伤较轻,突触数目较多,突触形态基本正常.结论:急性期腹腔注射NGF可减轻大鼠脑缺血性损伤程度,可能通过增加脑组织Syp的表达来促进脑缺血性损伤后突触的形成.