Maggi A, Perez J
J Neurochem. 1986 Dec;47(6):1793-7. doi: 10.1111/j.1471-4159.1986.tb13090.x.
Previous studies have identified an effect of estrogen administration on the number of central GABAergic binding sites of rat. We have further characterized this effect by performing a series of experiments in vitro where we analyzed the changes of gamma-aminobutyric acid (GABA) binding in slices of nervous tissue incubated in a physiological medium in presence of estradiol. The tissues were dissected from ovariectomized rats. In such a system, estrogen augmented the amount of [3H]muscimol binding within 3 h of incubation. The effect was dose-dependent and could be blocked by the addition of the anti-estrogen tamoxifen. The increase in [3H]muscimol binding could not be observed by addition of estradiol to broken membranes or by incubation of the slices with steroids deprived of estrogenic activity. Furthermore, the estrogen-induced increase of GABA binding sites could be prevented by addition of cycloheximide and alpha-amanitin in the incubation medium. Our data indicate that the estrogen may increase the number of GABA binding sites by direct interaction with the GABA receptor gene or genes involved in the metabolism of GABA receptor.
先前的研究已经确定了给予雌激素对大鼠中枢γ-氨基丁酸（GABA）能结合位点数量的影响。我们通过在体外进行一系列实验进一步表征了这种影响，在这些实验中，我们分析了在生理培养基中于雌二醇存在下孵育的神经组织切片中γ-氨基丁酸（GABA）结合的变化。组织取自卵巢切除的大鼠。在这样的系统中，雌激素在孵育3小时内增加了[3H]蝇蕈醇的结合量。这种作用是剂量依赖性的，并且可以通过添加抗雌激素他莫昔芬来阻断。向破碎的膜中添加雌二醇或用缺乏雌激素活性的类固醇孵育切片均未观察到[3H]蝇蕈醇结合的增加。此外，在孵育培养基中添加放线菌酮和α-鹅膏蕈碱可以阻止雌激素诱导的GABA结合位点增加。我们的数据表明，雌激素可能通过与GABA受体基因或参与GABA受体代谢的基因直接相互作用来增加GABA结合位点的数量。
