去卵巢后大鼠基底前脑NOS阳性神经元的变化及雌激素的作用

目的　研究基底前脑NOS阳性神经元在大鼠去卵巢之后的时程变化 ,为雌激素类药物替代防治绝经后老年性痴呆提供理论依据。方法　将 6 9只 3月龄雌性大鼠随机分为假手术组、去卵巢对照组及雌激素替代治疗组 ,各 2 3只 ,分别在术后 3d、1周、2周、4周、8周处死 ,脑切片用NADPH d组化方法染色 ,观察并和计数基底前脑各区NOS阳性神经元 ,并进行统计分析。结果　各组大鼠基底前脑各区NOS阳性神经元数目在去卵巢后先上升 ,2周时达到高峰 ,以后假手术组及雌激素替代组NOS阳性神经元数目逐渐下降 ,8周时达正常水平。去卵巢对照组斜角带核水平支及垂直支NOS阳性神经元数目却保持较高水平 ,在 8周时与假手术组及雌激素替代治疗组之间差异有显著性 (P <0 0 1)。结论　去卵巢后基底前脑NOS阳性神经元表达增加 ,而雌激素替代治疗对其有保护作用。

Changes of NOS positive neurons of basal forebrain of ovariectomized rats and the effect of estrogen

Objective To explore the timely changes of NOS positive neurons of basal forebrain after ovariectomize operation and to provide basic theories for preventing and treating Alzheimer′s disease with estrogen.Methods Sixty-nine 3-month-old Sprague-Dawley rats were divided randomly into three groups:sham operated, ovariectomized and estradiol benzoate replaced groups. Each group has 23 rats. The rats were sacrifice 3 days,1 weeks,2 weeks,4 weeks and 8 weeks after operation respectively. The brain sections were stained by NADPH-diaphorase histochemistry and the positive neurons of basal forebrain were counted and statistically analysised.Results All the NOS positive neurons of basal forebrain were ascended after operation, until they reached the peak in two weeks. Then the numbers of NOS positive neurons of sham-operated and estradiol benzoate replaced groups were descended till they reached the normal level 8 weeks after operation, But the NOS positive neurons of VDB and HDB of ovariectomized groups were stayed at a higher level, which have significant difference comparing with sham-operated and estradiol benzoate replaced groups in 8 weeks after operation(P<0.01). Conclusions The changes of NOS positive neurons of basal forebrain after ovariectomized take the responsibility to the changes of learning and memory of ovariectomized rats. Estrogen replacement therapy must be performed early.