Watson J T, Adkins-Regan E
Department of Psychology, Cornell University, Ithaca, New York 14853.
Horm Behav. 1989 Sep;23(3):432-47. doi: 10.1016/0018-506x(89)90055-x.
Intracranial implantation of minute pellets of gonadal steroids was combined with aromatase inhibitor treatment to determine if aromatization within the preoptic area (POA) is necessary for androgens to activate sexual behavior in the Japanese quail (Coturnix japonica). In this species, implantation of pellets of testosterone propionate (TP) or estradiol benzoate (EB) in the POA of castrated males restores male-typical copulatory behavior. In Experiment 1, adult male castrated quail were implanted intracranially with 200-micrograms pellets of equimolar mixtures of crystalline TP + cholesterol (CHOL), TP + 1,4,6-androstatriene-3,17-dione (ATD, an aromatase inhibitor), EB + ATD, or CHOL and behavior-tested with intact males and females. Copulation was stimulated by POA implants containing TP or EB (three of six CHOL + TP males and two of seven ATD + EB males copulated vs zero of four CHOL males), but copulation was not inhibited by combining ATD with TP (three of four ATD + TP males copulated). In Experiment 2, adult male castrated quail were injected systemically with ATD or oil for 6 days prior to and 14 days after intracranial implantation of 200-micrograms pellets containing the same amounts of TP or EB as in Experiment 1. The ATD injections completely blocked copulatory behavior in males with TP implants in the POA such that ATD/TP and Oil/TP mount frequencies differed significantly, but failed to block copulation in males with EB implants in the POA (proportions of males copulating were ATD/EB, 6/8; ATD/TP, 0/6; Oil/TP, 4/7). The cloacal foam gland, an androgen-sensitive secondary sex character, was unaffected by the dose of ATD used. We conclude that activation of copulatory behavior by TP implants in the POA is not due to nonspecific effects of high local testosterone concentrations but rather to aromatization. These results support the hypothesis that cells within the POA aromatize testosterone to estrogens, which directly stimulate the cellular processes leading to activation of male-typical copulatory behavior.
将性腺类固醇微小丸剂颅内植入与芳香化酶抑制剂治疗相结合，以确定视前区（POA）内的芳香化作用对于雄激素激活日本鹌鹑（Coturnix japonica）的性行为是否必要。在该物种中，向阉割雄性的POA植入丙酸睾酮（TP）或苯甲酸雌二醇（EB）丸剂可恢复雄性典型的交配行为。在实验1中，成年阉割雄性鹌鹑颅内植入200微克结晶TP + 胆固醇（CHOL）、TP + 1,4,6 - 雄甾三烯 - 3,17 - 二酮（ATD，一种芳香化酶抑制剂）、EB + ATD或CHOL的等摩尔混合物丸剂，并与完整的雄性和雌性进行行为测试。含有TP或EB的POA植入物刺激了交配行为（六个CHOL + TP雄性中有三个、七个ATD + EB雄性中有两个交配，而四个CHOL雄性中无一交配），但将ATD与TP联合使用并未抑制交配行为（四个ATD + TP雄性中有三个交配）。在实验2中，成年阉割雄性鹌鹑在颅内植入与实验1中相同量的TP或EB的200微克丸剂之前6天和之后14天，全身注射ATD或油。ATD注射完全阻断了POA中有TP植入物的雄性的交配行为，使得ATD/TP和油/TP的骑跨频率有显著差异，但未能阻断POA中有EB植入物的雄性的交配行为（交配雄性的比例为ATD/EB，6/8；ATD/TP，0/6；油/TP，4/7）。泄殖腔泡沫腺是一种对雄激素敏感的第二性征，不受所用ATD剂量的影响。我们得出结论，POA中TP植入物激活交配行为不是由于局部高睾酮浓度的非特异性作用，而是由于芳香化作用。这些结果支持以下假设：POA内的细胞将睾酮芳香化为雌激素，雌激素直接刺激导致雄性典型交配行为激活的细胞过程。
