Paden C M, Roselli C E
Brain Res. 1987 May;430(1):127-33. doi: 10.1016/0165-3806(87)90182-9.
Conversion of androgens to estrogens by neural aromatase appears to be a prerequisite for a variety of effects of androgens on brain function, including sexual differentiation. Activity of aromatase is modulated by its substrate testosterone (T) in adult hypothalamus-preoptic area (HPOA), resulting in significantly higher levels in the male. Perinatal sex differences in activity have also been observed in hypothalamus, POA and/or amygdala. However, it is not known if higher levels in the perinatal male occur in response to circulating androgens, nor whether early exposure to gonadal steroids is necessary to establish either basal levels or the androgen sensitivity of aromatase activity in the adult brain. In order to investigate the influence of early steroid exposure on the development of neural aromatase activity, embryonic day (E)17 fetal HPOA was transplanted onto the choroidal pia overlying the superior colliculus of adult ovariectomized-adrenalectomized (OVX-ADX) Holtzman female hosts. In the first experiment, the effect of androgen exposure on aromatase activity in mature HPOA transplants was determined. Hosts received T-filled silastic capsules or underwent sham surgery 7 weeks after transplantation and were sacrificed 7 days later. Aromatase activity was determined in vitro using the stereospecific production of 3H2O from [1 beta-3H]androstenedione as an index of estrogen formation. Aromatase activity was significantly greater in T-treated HPOA versus controls (P less than 0.005). Activity was not affected by the sex of the donor fetus. In the second experiment, the effect of androgen exposure during the first 6 days following transplantation of E17 HPOA (corresponding to the last gestational week) was determined.(ABSTRACT TRUNCATED AT 250 WORDS)
神经芳香化酶将雄激素转化为雌激素似乎是雄激素对脑功能产生多种影响（包括性分化）的一个先决条件。在成年下丘脑 - 视前区（HPOA），芳香化酶的活性受其底物睾酮（T）调节，导致男性体内的水平显著更高。在下丘脑、视前区和/或杏仁核中也观察到围产期活性的性别差异。然而，尚不清楚围产期男性体内较高水平是否是对循环雄激素的反应，也不清楚早期接触性腺类固醇对于建立成年大脑中芳香化酶活性的基础水平或雄激素敏感性是否必要。为了研究早期类固醇暴露对神经芳香化酶活性发育的影响，将胚胎第17天（E17）的胎儿HPOA移植到成年去卵巢 - 去肾上腺（OVX - ADX）的霍尔兹曼雌性宿主上丘上方的脉络丛软脑膜上。在第一个实验中，确定了雄激素暴露对成熟HPOA移植体中芳香化酶活性的影响。宿主在移植后7周接受填充T的硅橡胶胶囊或进行假手术，并在7天后处死。使用[1β - 3H]雄烯二酮立体特异性生成3H2O作为雌激素形成指标，在体外测定芳香化酶活性。与对照组相比，T处理的HPOA中芳香化酶活性显著更高（P小于0.005）。活性不受供体胎儿性别的影响。在第二个实验中，确定了在E17 HPOA移植后（相当于妊娠最后一周）的前6天内雄激素暴露的影响。（摘要截断于250字）
