Arteaga-Silva M, Vigueras-Villaseñor R M, Retana-Márquez S, Hernández-González M, Chihuahua-Serrano C, Bonilla-Jaime H, Contreras J L, Moralí G
Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana, Iztapalapa, P.O. Box 55535, México 09340 D.F., Mexico.
Physiol Behav. 2008 Jun 9;94(3):412-21. doi: 10.1016/j.physbeh.2008.02.007. Epub 2008 Feb 20.
The expression of masculine sexual behavior (MSB) in male hamsters is optimally stimulated by aromatizable androgens like androstenedione (AD) and testosterone (T), while the non-aromatizable androgen, 5alpha-dihydrotestosterone (DHT), exerting potent androgenic peripheral effects, only in high doses maintains MSB after castration. No data exist on the ability of these androgens to restore long intromissions after castration. In this study, AD, T, and DHT were administered to four-week gonadectomized, sexually experienced male hamsters, for three weeks, in doses of 25 microg/day or up to 1000 microg/day to compare their potency in restoring MSB, penile size, and penile spines growth. Plasma levels of these steroids and the metabolites estrone and estradiol, were determined at the end of the treatment period. Gonadectomy completely suppressed MSB and induced a regression of penile spines. AD was more potent than T in restoring MSB, ejaculatory behavior being displayed by most castrated subjects with a lower dose of AD (50 microg/day) than of T (300 microg/day), and long intromissions being shown by all AD-treated castrated hamsters but only by 20% of T-treated ones, when doses of 1000 microg/day were given. DHT did not stimulate any copulatory response. The three androgens, even at the lowest dose, partially stimulated penis and penile epithelium growth, DHT showing the highest potency. Treatment of castrated hamsters with AD (50 microg/day), restored steroid levels to similar values as those of intact animals. These results show that AD and T restored MSB even with a partial stimulation of penile spines growth, AD being more potent than T. In contrast, DHT did not restore MSB in the hamster in spite of its peripheral androgenic potency.
在雄性仓鼠中，可芳香化的雄激素如雄烯二酮（AD）和睾酮（T）能最佳地刺激雄性性行为（MSB）的表达，而不可芳香化的雄激素5α-二氢睾酮（DHT）虽具有强大的雄激素外周效应，但仅在高剂量时才能在去势后维持MSB。目前尚无关于这些雄激素恢复去势后长时间插入行为能力的数据。在本研究中，将AD、T和DHT给予四周龄去势且有性经验的雄性仓鼠，持续三周，剂量为每天25微克或高达1000微克，以比较它们在恢复MSB、阴茎大小和阴茎棘生长方面的效力。在治疗期结束时测定这些类固醇以及代谢产物雌酮和雌二醇的血浆水平。去势完全抑制了MSB并导致阴茎棘退化。在恢复MSB方面，AD比T更有效，大多数去势受试者在较低剂量的AD（每天50微克）下就能表现出射精行为，而T（每天300微克）则不行；当给予每天1000微克的剂量时，所有接受AD治疗的去势仓鼠都表现出长时间插入行为，而接受T治疗的只有20%表现出该行为。DHT未刺激任何交配反应。这三种雄激素即使在最低剂量时也能部分刺激阴茎和阴茎上皮生长，DHT的效力最高。用AD（每天50微克）治疗去势仓鼠可使类固醇水平恢复到与完整动物相似的值。这些结果表明，AD和T即使在部分刺激阴茎棘生长的情况下也能恢复MSB，AD比T更有效。相比之下，DHT尽管具有外周雄激素效力，但在仓鼠中并未恢复MSB。
