Development and hormone regulation of androgen receptor levels in the sexually dimorphic larynx of Xenopus laevis.
Development and hormone regulation of androgen receptor levels in the sexually dimorphic larynx of Xenopus laevis.
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非洲爪蟾两性异形喉中雄激素受体水平的发育和激素调节。
DOI：
10.1016/s0012-1606(89)80042-9
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发表时间：
1989
影响因子：
2.7
通讯作者：
Scudder,M
中科院分区：
文献类型：
--
作者：
Kelley,D;Sassoon,D;Segil,N;Scudder,M
非洲爪蛙的性二形喉的发育是由雄激素类固醇的分泌控制的（D。Sassoon和D. Kelley，1986，Amer.J.Anat177，457-472）。成人喉肌显示出高水平的雄激素结合相对于其他骨骼肌和结合活性的男性是女性的三倍（N。塞吉尔湖Silverman和D. Kelley，1987，Gen.Comp.Endocrinol.66，95-101）。为了确定雄激素敏感性和性别差异出现时，我们测定了[3 H]双氢睾酮（DHT）的结合活性从变性和变性后的男性和女性青蛙的喉咙。Scatchard分析表明，双氢睾酮结合到一个具有高亲和力的饱和成分。在变态，男性和女性青少年的平均结合水平分别为262和269 fmoles/mg蛋白质，大约7至20倍的成年值。在3个月后变态（PM），观察到性二态结合水平。从变态到9月龄，雌虫的结合活性逐渐下降。在雄性中，结合活性水平在前6个月PM期间保持较高水平，然后在9个月PM时降至接近成年水平。给3个月PM青少年施用外源性DHT可使两性的平均结合活性从180（男性）或74 fmol/mg（女性）降低至33.5 fmol/mg。替吉奥在男性中对结合活性的影响不如DHT明显，在女性中无效。我们的结论是，性二态成人水平的雄激素结合在喉产生的差异减少，从最初的高，性单态水平和高滴度的循环雄激素通常存在于6个月PM的男性负责喉发育过程中观察到的结合活性显着下降。
Development of the sexually dimorphic larynx in African clawed frogs is controlled by secretion of androgenic steroids (D. Sassoon and D. Kelley, 1986,Amer. J. Anat177, 457–472). Adult laryngeal muscle shows high levels of androgen binding relative to other skeletal muscles and binding activity in males is three times that in females (N. Segil, L. Silverman, and D. Kelley, 1987,Gen. Comp. Endocrinol.66, 95–101). To determine when androgen sensitivity and sex differences arise, we assayed [3H]dihydrotestosterone (DHT) binding activity in larynges from metamorphic and postmetamorphic male and female frogs. Scatchard analyses indicate that DHT binds to a saturable component with high affinity. At metamorphosis, male and female juveniles have average binding levels of 262 and 269 fmoles/mg protein, respectively, approximately 7 to 20 times their adult values. At 3 months postmetamorphosis (PM), sexually dimorphic binding levels are observed. Binding activity declines gradually in females from metamorphosis to 9 months PM. In males, levels of binding activity remain high throughout the first 6 months PM and then decrease to near adult levels by 9 months PM. Administration of exogenous DHT to 3 months PM juveniles decreases average binding activity from 180 (male) or 74 fmoles/mg (female) to 33.5 fmoles/mg in both sexes. Testosterone has a less pronounced effect on binding activity in males than DHT and is ineffective in females. We conclude that sexually dimorphic adult levels of androgen binding in larynx arise by differential decrease from initially high, sexually monomorphic levels and that high titers of circulating androgens normally present by 6 months PM in males are responsible for the marked decrease in binding activity observed during laryngeal development.