Zumpe D, Michael R P
Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322.
Physiol Behav. 1994 Oct;56(4):665-9. doi: 10.1016/0031-9384(94)90224-0.
Our previous studies showed that treating castrated, testosterone-treated male cynomolgus monkeys with Depo-Provera (medroxyprogesterone acetate, MPA) decreased ejaculatory performance and also measures of male sexual motivation by about 40%. Similarly, treating castrated, testosterone-treated males with the nonsteroidal aromatase inhibitor, Fadrozole, decreased ejaculatory performance and male sexual motivation again by about 40%. These behavioral decrements are, of course, mediated by totally different mechanisms. We have therefore hypothesized that both unchanged T and E2 might be important for the control of sexual behavior in this male primate, and the present study examined the consequences of administering Fadrozole at a dose of 0.25 mg/kg/day to intact male cynomolgus monkeys being treated with 40 mg/week MPA. Intact males were each tested with an ovariectomized, E2-treated female partner (i) before treatment, (ii) during treatment with MPA alone, and (iii) during treatment with MPA and either Fadrozole or water administered SC by osmotic minipumps. As in previous studies, MPA significantly decreased plasma T levels and sexual behavior. But additional treatment with Fadrozole resulted in a rapid increase in plasma T levels although causing a further decline in sexual behavior. Results supported the view that both unchanged T and its aromatized product are important for ejaculatory activity and sexual motivation in the primate. Fadrozole's effect on plasma T may have been due to the elimination of the negative feedback of E2 on the hypothalamic-pituitary-gonadal axis.
我们之前的研究表明，给去势且接受睾酮治疗的雄性食蟹猴注射醋酸甲羟孕酮（Depo-Provera，MPA）会使射精能力以及雄性性动机指标下降约40%。同样，给去势且接受睾酮治疗的雄性食蟹猴使用非甾体芳香化酶抑制剂法倔唑（Fadrozole），射精能力和雄性性动机也再次下降约40%。当然，这些行为变化是由完全不同的机制介导的。因此，我们推测未改变的睾酮（T）和雌二醇（E2）可能对这种雄性灵长类动物的性行为控制都很重要，本研究检测了以0.25毫克/千克/天的剂量给每周接受40毫克MPA治疗的完整雄性食蟹猴注射法倔唑的后果。完整雄性食蟹猴分别与一只去势且接受E2治疗的雌性伴侣进行测试：（i）治疗前，（ii）仅接受MPA治疗期间，以及（iii）在接受MPA治疗且通过渗透微型泵皮下注射法倔唑或水期间。与之前的研究一样，MPA显著降低了血浆T水平和性行为。但额外使用法倔唑治疗导致血浆T水平迅速升高，尽管性行为进一步下降。结果支持了以下观点，即未改变的T及其芳香化产物对灵长类动物的射精活动和性动机都很重要。法倔唑对血浆T的影响可能是由于消除了E2对下丘脑-垂体-性腺轴的负反馈作用。
