Department of Zoology, Michigan State University, East Lansing, MI 48824-1101, USA.
Gen Comp Endocrinol. 2010 Mar 1;166(1):128-33. doi: 10.1016/j.ygcen.2009.11.006. Epub 2009 Nov 14.
Testosterone (T) and its metabolites are important in the regulation of reproductive behavior in males of a variety of vertebrate species. Aromatase converts T to estradiol and 5alpha-reductase converts T to 5alpha-dihydrotestosterone (DHT). Male green anole reproduction depends on androgens, yet 5alpha-reductase in the brain is not sexually dimorphic and does not vary with season. In contrast, aromatase activity in the male brain is increased during the breeding compared to non-breeding season, and males have higher levels than females during the breeding season. Aromatase is important for female, but not male, sexual behaviors. The present experiment was conducted to determine whether 5alpha-reductase and aromatase are regulated by T. Enzyme activity was quantified in whole brain homogenates in both the breeding and non-breeding seasons in males and females that had been treated with either a T or blank implant. In males only, T increased 5alpha-reductase activity regardless of season and up-regulated aromatase during the breeding season specifically. Thus, regulation of both enzymes occurs in males, whereas females do not show parallel sensitivity to T. When considered with previous results, the data suggest that aromatase might influence a male function associated with the breeding season other than sexual behavior. 5alpha-Reductase can be mediated by T availability, but this regulation may not serve a sex- or season-specific purpose.
睾酮（T）及其代谢物在调节各种脊椎动物雄性的生殖行为中起着重要作用。芳香化酶将 T 转化为雌二醇，5α-还原酶将 T 转化为 5α-二氢睾酮（DHT）。雄性绿鬣蜥的繁殖依赖于雄激素，但大脑中的 5α-还原酶没有性别二态性，也不受季节变化的影响。相比之下，雄性大脑中的芳香酶活性在繁殖期比非繁殖期增加，而且在繁殖期雄性的水平高于雌性。芳香酶对雌性但不是雄性的性行为很重要。本实验旨在确定 5α-还原酶和芳香酶是否受 T 调节。在繁殖期和非繁殖期，用 T 或空白植入物处理的雄性和雌性的全脑匀浆中定量测定了两种酶的活性。仅在雄性中，T 增加了 5α-还原酶活性，无论季节如何，并且在繁殖期特异性地上调了芳香酶。因此，两种酶都受到调节，而雌性对 T 没有表现出平行的敏感性。当与以前的结果一起考虑时，这些数据表明，芳香酶可能会影响与繁殖季节相关的男性功能，而不是性行为。5α-还原酶可由 T 的可用性介导，但这种调节可能没有特定的性别或季节目的。
