植物雌激素对去卵巢血管性痴呆大鼠认知功能和海马胆碱乙酰转移酶表达的影响

摘要

目的:观察植物雌激素对去卵巢血管性痴呆(VD)大鼠海马胆碱能神经元表达的影响,探讨植物雌激素对去卵巢VD大鼠的脑保护作用及可能机制.方法:60只雌性Wistar大鼠经水迷宫筛选随机分为4组.Ⅰ组(sham组):VD大鼠,未去除卵巢;Ⅱ组(OVX组):VD大鼠,去除卵巢;Ⅲ组(OVX+est组):VD大鼠,去除卵巢,给予化学雌激素喂养;Ⅳ组(OVX+phy组):去除卵巢,给予植物雌激素喂养.4组大鼠VD手术前后分别应用Morris水迷宫检测法进行大鼠空间认知功能的评价.采用胆碱乙酰转移酶(ChAT)免疫组织化学ABC法,观察去卵巢VD大鼠各组海马胆碱能神经元的数目.结果:与OVX组相比,OVX+est组及OVX+phy组的大鼠海马胆碱能神经元数目明显升高(P＜0.05),且在水迷宫中找到水下平台的时间、距离明显缩短(P＜0.05),而与sham对照组差别不明显,且OVX+est组和OVX+phy组相比较,无显著性差异(P＞0.05).结论:植物雌激素具有雌激素样作用,能增强大鼠海马胆碱能神经元的ChAT表达,对血管性痴呆大鼠的记忆损害有一定程度的保护作用.%Objective: To study the effect of phytoestrogen on cholinergic neurons in hippocampus formation of ovariectomized and vascular dementia (VD) rats in order to explore the protection; on mechanism of phytoestrogen on the central nervous system.Method: Sixty female Wistar rats were randomly divided into 4 groups. Sham group: treated with sham operation of ovariectomy; OVX group: ovariectomized and made into the model of VD; OVX+estrogen group: ovariectomized and made into the model of VD, and supplied with estrogen; OVX+phytoestrogen group:ovariectomized and made into the model of VD, and fed with phytoestrogen. Cognizing memory ability of rats was tested respectively in Morris water maze before and after operation of VD. The amount of cholinergic neurons was observed by using choline-acetyltransferase(ChAT) immunohistochemical SABC methods in CA1 region of hippocampus formation.Result: The amount of cholinergic neurons in sham group, OVX+estrogen group, OVX+phytoestrogen group was significantly higher than that in OVX group in CA1 region of hippocampus formation in central nervous system of rats(P＜0.05). Morris water maze test showed that latency, swimming distance for searching submerged platform decreased significantly(P＜0.05). The amount of cholinergic neurons and the data of latency, swimming distance for searching submerged platform in sham group, OVX+estrogen group, OVX+phytoestrogen group were not different significantly(P＞0.05).Conclusion: The results indicated that phytoestrogen and estrogen replacement therapy could obviously elevate cholinergic neurons expression in hippocampus of ovariectomized VD rats, so phytoestrogen could protect the damage of cognizing memory ability in VD rats.