Melatonin stimulates growth hormone secretion through pathways other than the growth hormone‐releasing hormone

作者：Roberto Valcavi, Michele Zini, Georges J. M. Maestroni, Ario Conti, Italo Portioli · 发表于：Clinical Endocrinology · 年份：1993 · DOI：10.1111/j.1365-2265.1993.tb01773.x · 被引用次数：91 · 研究领域：Growth Hormone and Insulin-like Growth Factors、Stress Responses and Cortisol、Regulation of Appetite and Obesity

OBJECTIVE: There is evidence that melatonin plays a role in the regulation of GH secretion. The aim of this study was to investigate the neuroendocrine mechanisms by which melatonin modulates GH secretion. Thus we assessed the effect of oral melatonin on the GH responses to GHRH administration and compared the effects of melatonin with those of pyridostigmine, a cholinergic agonist drug which is likely to suppress hypothalamic somatostatin release. DESIGN: The study consisted of four protocols carried out during the afternoon hours. Study 1: oral melatonin (10 mg) or placebo were administered 60 minutes prior to GHRH (100 micrograms i.v. bolus). Study 2: GHRH (100 micrograms i.v. bolus) or placebo were administered at 0 minutes; oral melatonin or placebo were given at 60 minutes and were followed by a second GHRH stimulus (100 micrograms i.v. bolus) at 120 minutes. Study 3: placebo; oral melatonin (10 mg); oral pyridostigmine (120 mg); melatonin (10 mg) plus pyridostigmine (120 mg) were administered on separate occasions. Study 4: placebo; oral melatonin (10 mg); oral pyridostigmine (120 mg); melatonin (10 mg) plus pyridostigmine (120 mg) were administered on separate occasions 60 minutes prior to a submaximal dose (3 micrograms i.v. bolus) of GHRH. SUBJECTS: Four groups of eight normal male subjects, ages 22-35 years, were randomly assigned to each protocol. MEASUREMENTS: Growth hormone was measured by RIA at 15-minute intervals. RESULTS: Oral melatonin administration had a ...