Dörner G, Döcke F, Götz F, Rohde W, Stahl F, Tönjes R
Institute of Experimental Endocrinology, Humboldt University Medical School (Charité), Berlin, German Democratic Republic.
J Steroid Biochem. 1987;27(4-6):1081-7. doi: 10.1016/0022-4731(87)90193-2.
The positive estrogen feedback was found to be a relatively sex-specific reaction of the hypothalamo-hypophyseal system in rats as well as in human beings. It is dependent--most of all--on the estrogen convertible androgen level during sexual brain differentiation, but also on an estrogen priming effect in adulthood. The lower the estrogen convertible androgen or primary estrogen level during brain differentiation, the higher is the evocability of a positive estrogen action on LH secretion in later life. In clinical studies, we were able to induce a positive estrogen feedback on LH secretion in most intact homosexual men in clear-cut contrast to intact hetero- or bisexual men. These findings were strongly confirmed by Gladue and associates. In addition, the evocability of a positive estrogen feedback was also demonstrable in most homosexual male-to-female transsexuals in significant contrast to hetero- or bisexual male-to-female transsexuals. These findings suggest that homosexual males possess, at least in part, a predominantly female-differentiated brain, which may be caused by a low estrogen convertible androgen level during brain organization. Recently, the following relations were found between sex hormone levels during brain differentiation and sex-specific responses in adulthood: (1) estrogens--which are mostly converted, however, from androgens--are responsible for the sex-specific organization of gonadotrophin secretion and hence the evocability of a positive estrogen feedback in later life; (2) estrogens and androgens, occurring during brain differentiation, predetermine synergistically sexual orientation and (3) androgens--without conversion to estrogens--are responsible for the sex-specific organization of gender role behaviour in later life. Furthermore, the organization periods for sex-specific gonadotrophin secretion, sexual orientation and gender role behaviour are not identical but overlapping. Thus, combinations as well as dissociations between deviations of the neuroendocrine organization of sex-specific gonadotrophin secretion, sexual orientation and gender role behaviour are conceivable. Most recently, female-type sexual orientation could be converted to male-type sexual orientation in adult rats by administration of the dopamine agonist and serotonin antagonist lisuride.
正性雌激素反馈被发现是大鼠以及人类下丘脑 - 垂体系统相对性别特异性的反应。它主要取决于性脑分化过程中可转化为雌激素的雄激素水平，也取决于成年期的雌激素启动效应。脑分化过程中可转化为雌激素的雄激素或初始雌激素水平越低，后期生活中雌激素对促黄体生成素（LH）分泌产生正性作用的可激发性就越高。在临床研究中，我们能够在大多数性取向正常的同性恋男性中诱导出对LH分泌的正性雌激素反馈，这与性取向正常的异性恋或双性恋男性形成鲜明对比。这些发现得到了格拉德等人的有力证实。此外，在大多数男变女的同性恋变性者中也可证实存在正性雌激素反馈的可激发性，这与男变女的异性恋或双性恋变性者形成显著对比。这些发现表明，同性恋男性至少部分拥有主要为女性分化的大脑，这可能是由于脑发育过程中可转化为雌激素的雄激素水平较低所致。最近，发现脑分化过程中的性激素水平与成年期的性别特异性反应之间存在以下关系：（1）雌激素——然而大多由雄激素转化而来——负责促性腺激素分泌的性别特异性组织，因此决定了后期生活中雌激素正性反馈的可激发性；（2）脑分化过程中出现的雌激素和雄激素协同预先决定性取向；（3）雄激素——无需转化为雌激素——负责后期生活中性别角色行为的性别特异性组织。此外，性别特异性促性腺激素分泌、性取向和性别角色行为的组织期并不相同而是重叠的。因此，可以想象性别特异性促性腺激素分泌、性取向和性别角色行为的神经内分泌组织偏差之间会出现组合以及分离的情况。最近，通过给予多巴胺激动剂和5 - 羟色胺拮抗剂利苏瑞得，成年大鼠的女性型性取向可转变为男性型性取向。
