Department of Medicine, University of Washington, 1959 NE Pacific Street, Box 357138, Seattle, Washington 98195, USA.
J Clin Endocrinol Metab. 2010 Aug;95(8):3806-13. doi: 10.1210/jc.2010-0360. Epub 2010 May 19.
In men with infertility secondary to gonadotropin deficiency, treatment with relatively high dosages of human chorionic gonadotropin (hCG) stimulates intratesticular testosterone (IT-T) biosynthesis and spermatogenesis. Previously we found that lower dosages of hCG stimulated IT-T to normal. However, the minimal dose of hCG needed to stimulate IT-T and the dose-response relationship between very low doses of hCG and IT-T and serum testosterone in normal men is unknown.
DESIGN, SETTING, PATIENTS, AND INTERVENTION: We induced experimental gonadotropin deficiency in 37 normal men with the GnRH antagonist acyline and randomized them to receive one of four low doses of hCG: 0, 15, 60, or 125 IU sc every other day or 7.5 g daily testosterone gel for 10 d. Testicular fluid was obtained by percutaneous aspiration for steroid measurements at baseline and after 10 d of treatment and correlated with contemporaneous serum hormone measurements.
Median (25th, 75th percentile) baseline IT-T was 2508 nmol/liter (1753, 3502 nmol/liter). IT-T concentrations increased in a dose-dependent manner with very low-dosage hCG administration from 77 nmol/liter (40, 122 nmol/liter) to 923 nmol/liter (894, 1017 nmol/liter) in the 0- and 125-IU groups, respectively (P<0.001). Moreover, serum hCG was significantly correlated with both IT-T and serum testosterone (P<0.01).
Doses of hCG far lower than those used clinically increase IT-T concentrations in a dose-dependent manner in normal men with experimental gonadotropin deficiency. Assessment of IT-T provides a valuable tool to investigate the hormonal regulation of spermatogenesis in man.
在因促性腺激素缺乏而导致不育的男性中，相对较高剂量的人绒毛膜促性腺激素（hCG）治疗可刺激睾丸内睾酮（IT-T）的生物合成和精子发生。我们之前发现，较低剂量的 hCG 可刺激 IT-T 恢复正常。然而，刺激 IT-T 所需的 hCG 的最小剂量以及正常男性中非常低剂量的 hCG 和 IT-T 与血清睾酮之间的剂量反应关系尚不清楚。
设计、设置、患者和干预：我们使用 GnRH 拮抗剂 acyline 在 37 名正常男性中诱导实验性促性腺激素缺乏症，并将他们随机分配接受以下四种低剂量 hCG 之一的治疗：0、15、60 或 125IU，每隔一天皮下注射一次，或每天 7.5g 睾酮凝胶，共 10 天。在基线和治疗 10 天后通过经皮抽吸获得睾丸液，用于类固醇测量，并与同期的血清激素测量相关联。
中位数（25 百分位，75 百分位）基线 IT-T 为 2508nmol/L（1753，3502nmol/L）。非常低剂量 hCG 给药后，IT-T 浓度呈剂量依赖性增加，0-和 125IU 组分别从 77nmol/L（40，122nmol/L）增加至 923nmol/L（894，1017nmol/L）（P<0.001）。此外，血清 hCG 与 IT-T 和血清睾酮均显著相关（P<0.01）。
在实验性促性腺激素缺乏的正常男性中，远远低于临床使用剂量的 hCG 剂量可剂量依赖性地增加 IT-T 浓度。评估 IT-T 为研究人类精子发生的激素调节提供了一种有价值的工具。
