雌激素对穹隆海马伞切断大鼠脑内nAchR的干预作用

目的以双侧穹隆-海马伞切断制作阿尔茨海默病(AD)大鼠模型,观察脑内海马CA1区和皮层区烟碱型乙酰胆碱受体(nAchR)表达的变化,探讨与AD相关的发病机制,并观察雌激素的干预作用。方法健康雌性W istar大鼠,随机分为3组:(1)穹隆-海马伞切断组;(2)雌激素治疗组;(3)假手术对照组;每组大鼠5只。在脑立体定位仪上切断穹隆-海马伞,建立模拟AD动物模型。应用免疫组织化学技术观察AD大鼠海马CA1区和皮层区的nAchR阳性细胞表达的变化,以及应用外源性雌激素的干预作用。结果与对照组大鼠脑内nAchR表达比较,穹隆-海马伞切断组大鼠脑内海马CA1区、皮层区nAchR表达显著减少(P<0.05);与穹隆-海马伞切断组比较,雌激素治疗组海马CA1区、皮层区nAchR表达显著增加(P<0.01),但与对照组比较无显著差异(P>0.05)。结论穹隆-海马伞切断组大鼠脑内海马CA1区、皮层区nAchR的阳性细胞显著减少,补充外源性雌激素治疗后,上述各脑区内的nAchR表达显著增加。nAchR的变化与AD的病理变化过程密切相关,补充雌激素可以干预这种病理过程。

Expression of nAchR in Brains of Ovariectomized Rats

Objective To observe the expression of nicotinic acetylcholine receptor(nAchR) in the brain's fimbria/fornix transected rats,the effect of ectogenic estrogen on it,and its relation with Alzhelmer's disease(AD).Methods Healthy female Wistar rats were divided into three groups at random:(1) fimbria/fornix transection group,(2) estrogen treatment group,and(3) control group.There were five rats in every group.And their fimbria/fornix was transected in order that AD models were made.Immunoreactive cells with nAchR were stained by immunohistochemical way so that the expression varieties of nAchR immunoreactive cells could be observed in hippocampus CA1 and cortex. Results In fimbria/fornix transection group,the expression of nAchR obviously decreased in the observed areas of the brain(P<0.05).In estrogen treatment group,the expression of nAchR increased remarkably(P<0.01).Conclusion The cells expressing nAchR clearly decrease in the areas of CA1 and cortex of rats when their fimbria/fornix is transected,but the cell number increases significanly if ectogenic estrogen is added.The change in nAchR is closely relative with AD whose pathological course can be influenced by the intervention of estrogen.