Boston University, Department of Biology, 2 Cummington Street, Boston, Massachusetts 02215, USA.
J Neuroendocrinol. 1989 Aug 1;1(4):265-71. doi: 10.1111/j.1365-2826.1989.tb00114.x.
Abstract Experiments were conducted to explore the possible relationship between testicular androgen secretion and the development of brain aromatase activity in fetal ferrets. Aromatase activity in the preoptic+mediobasal hypothalamus and temporal lobe was similar in fetuses of both sexes between embryonic Days 26 and 36 even though whole body androgen content was invariably higher in males than females. Whole body androgen content was significantly higher in females located caudally (downstream) from two or more as opposed to zero or one males in the same uterine horn; nevertheless their brain aromatase activity was similar. Finally, maternal treatment with either the androgen receptor antagonist Flutamide or 5alpha-dihydrotestosterone propionate beginning on gestational Day 24 did not affect brain aromatase activity in fetal offspring of either sex, delivered on embryonic Day 34. Previous studies suggest that the biosynthesis of estrogen in the fetal ferret brain is normally greater in males than females. The present results suggest that this sex difference results primarily from increased androgenic substrate being available to non-saturated aromatizing enzymes and not from an androgen-dependent activation of aromatase.
本实验旨在探索睾丸雄激素分泌与胎儿雪貂脑中芳香酶活性发育之间的可能关系。在胚胎第 26 天至 36 天之间，雄性和雌性胎儿的视前区+中脑基底部下丘脑和颞叶中的芳香酶活性相似，尽管雄性的全身雄激素含量始终高于雌性。在同一子宫角中，位于 2 个或更多个雄性下游的雌性的全身雄激素含量明显高于位于 0 个或 1 个雄性下游的雌性；然而，它们的大脑芳香酶活性相似。最后，母体从妊娠第 24 天开始用雄激素受体拮抗剂氟他胺或 5α-二氢睾酮丙酸处理，不会影响 34 日龄胚胎时雄性和雌性后代的大脑芳香酶活性。先前的研究表明，在雄性胎儿雪貂的大脑中，雌激素的生物合成通常比雌性更多。本研究结果表明，这种性别差异主要是由于非饱和芳香化酶的雄激素底物增加，而不是雄激素依赖性的芳香酶激活所致。
