不同剂量雌激素对去势雌性大鼠海马Bcl-2和Bax蛋白表达的影响

目的分析不同剂虽17β-雌二醇（17β-estradiol，E2）干预的去势雌性大鼠海马神经元凋亡相关蛋白Bcl-2及Bax的表达，探讨雌激素的神经元保护作用及其可能机制。方法将大鼠随机分为3组：假手术组（A组）、去卵巢组（B组）、E2干预组（C组），C组再随机分为3个剂量组。每组分别给予相应处理6周后处死。用放射免疫法（RIA）测定各组大鼠血清E2水平，采用免疫组织化学法（SP法）检测海马神经元Bcl-2及Bax蛋白的表达。结果与假手术组相比，去卵巢后大鼠海马Bcl-2蛋白表达降低（P〈0．01），补充外源性雌激素后Bcl-2蛋白表达逐渐恢复至正常水平；去卵巢后大鼠海马Bax蛋白表达升高（P〈0．01），补充外源性雌激素后Bax蛋白表达逐渐恢复至正常水平。结论雌激素能够不同程度的上调海马Bcl-2蛋白的表达，下调Bax蛋白的表达，从而对海马神经元具有保护作用。

Effects of various doses of estrogen on the expression of Bcl-2 and Bax proteins in hippocampus of ovariectomized female rats

Objective To analyze the expression of Bcl-2 and Bax, apoptosis-related proteins, in hippocampal neurons of ovariectomized （OVX） rats treated with various doses of 17β-estradiol in order to further investigate the mechanism of the cerebral protective effect of estrogen. Methods 25 Wistar rats were randomly divided into Sham group （group A）, OVX group （group B）, various doses of E2-treated groups （group C）, and group C was randomly divided into three groups, 5 rats each group, 5 rats each group. Six weeks later, the serum estradiol levels of each group were detected by radioimmunity analysis. Immunohistochemistry were used to examine the expression Bcl-2 and Bax in hippocampal neurons. Results Compare with Sham group, the expression of Bcl-2 and Bax proteins in hippocampus of the ovariectomized rats were down-regulated and up-regulated, respectively, while the expression of the two proteins was regulated to normal after the rats were treated with 17β-estradiol. Conclusion 17β-estradiol can prevent the neuron of hippocampus from excessive apoptosis by up-regulating the expression of Bcl-2 and down-regulating Bax in different levels.