Mandal H, Ghosh P K, Biswas N M
Department of Physiology, University of Calcutta, India.
J Endocrinol. 1990 Sep;126(3):431-5. doi: 10.1677/joe.0.1260431.
Adult male rats were given s.c. injections of melatonin (400 micrograms/100 g body weight per day) for 14 days. On day 15, the weights of the testis and accessory sex organs were less, testicular 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity was inhibited, spermatogenesis was suppressed and serum levels of gonadotrophins, testosterone and alpha 2u-globulin were decreased compared with control animals injected with vehicle. In a third group of rats given the same dose of melatonin for 14 days, administration of dihydrotestosterone (DHT) at a dose of 25 micrograms/100 g body weight per day on days 8-14 resulted in serum levels of alpha 2u-globulin, FSH, LH and testosterone and testicular 17 beta-HSD activity similar to those seen in vehicle-injected control animals. Weights of the testes and accessory sex organs and spermatogenesis were normal after administration of DHT in melatonin-treated rats. In another group of rats, the depressive effects of melatonin treatment on plasma gonadotrophins were reversed by the administration of alpha 2u-globulin on days 8-14. It was concluded that treatment with DHT prevents the depressive action of melatonin on testicular function by inducing the synthesis of alpha 2u-globulin.
成年雄性大鼠皮下注射褪黑素（每天400微克/100克体重），持续14天。在第15天，与注射赋形剂的对照动物相比，睾丸和附属生殖器官的重量减轻，睾丸17β-羟基类固醇脱氢酶（17β-HSD）活性受到抑制，精子发生受到抑制，促性腺激素、睾酮和α2u球蛋白的血清水平降低。在第三组大鼠中，给予相同剂量的褪黑素14天，在第8 - 14天每天以25微克/100克体重的剂量给予双氢睾酮（DHT），其α2u球蛋白、促卵泡激素（FSH）、促黄体生成素（LH）和睾酮的血清水平以及睾丸17β-HSD活性与注射赋形剂的对照动物相似。在褪黑素处理的大鼠中给予DHT后，睾丸和附属生殖器官的重量以及精子发生均正常。在另一组大鼠中，在第8 - 14天给予α2u球蛋白可逆转褪黑素处理对血浆促性腺激素的抑制作用。得出的结论是，DHT治疗通过诱导α2u球蛋白的合成来防止褪黑素对睾丸功能的抑制作用。
