17β-雌二醇对血管性痴呆大鼠海马CA1区神经突触可塑性的影响

Effect of 17β-estradiol on plasticity of nervous synaps in CA1 region of hippocampal of VD rats

目的探讨突触可塑性在17β-雌二醇改善血管性痴呆(VD)大鼠认知功能障碍中所起的作用。方法选用>16月龄雄性Wistar大鼠,应用Y迷宫进行空间定向学习和记忆训练,将达到标准者随机分为3组:(1)假手术(Sham)组;(2)VD组;(3)VD+雌二醇腹部皮下注射(E)组。应用免疫组织化学染色及RT-PCR的方法,检测大鼠海马CA1区微管相关蛋白2(MAP-2)和突触素(SYN)蛋白含量和mRNA表达水平的改变。结果术后60d,E组和VD组MAP-2和SYN表达均有下降,但VD组下降更为明显。结论 17β-雌二醇相对增加VD大鼠海马CA1区MAP-2、SYN蛋白含量和mRNA的表达。提示相对增加与突触可塑性相关的MAP-2、SYN蛋白含量和mRNA的表达,可能是雌二醇改善VD认知功能障碍的机制之一。

Objective To estimate the plasticity of nervous synapse on improving the cognitive dysfunction of VD rats with 17β-estradiol treatment. Methods The male Wistar rats over 16 months were trained to develop special study and memory with Y-maze. Rats reached to standards were randomly divided into 3 groups： sham operation group; VD group; VD＋estradiol abdominal hypodermic injection treatment （E） group. The changes of MAP-2 and SYN protein were observed by immunohistochemistry stain. The expression rate of MAP-2 and SYN mRNA were estimated with RT-PCR. Results Sixty days after operation, there was obvious decrease in MAP-2 and SYN expression in both groups and it was much more for VD group. Conclusion 17β-estradiol can comparatively increase the MAP-2 and SYN protein content and mRNA expression in the hippocampal CA1 region of VD rats. This shows that it can comparatively increase the MAP-2 and SYN protein content and mRNA expression which are relevant to the plasticity of nervous synapse, so, it may be one of mechanism of 17β-estradiol in improving the VD cognitive dysfunction.