Mendelson W B, Jacobs L S, Reichman J D, Othmer E, Cryer P E, Trivedi B, Daughaday W H
J Clin Invest. 1975 Sep;56(3):690-7. doi: 10.1172/JCI108139.
Methysergide, a clinically-used blocker of serotonin receptors, was administered to 10 normal young men at a dose of 2 mg every 6 h for 48 h. After drug treatment, serum levels of growth hormone during sleep were 41.9% higher than placebo values (less than 0.001). In contrast, drug treatment was associated with a 36.4% decrease in stimulated growth hormone secretion during insulin tolerance testing (P less than 0.01). These opposite effects of methysergide suggest that different mechanisms are responsible for sleep-related and insulin-induced growth hormone secretion. Accordingly, data obtained with pharmacologic stimuli may lead to erroneous inferences regarding physiologic growth hormone control mechanisms. Administration of methysergide profoundly suppressed sleep-related prolactin secretion; overall nocturnal mean prolactin fell by 70.3% from 4.30+/-0.19 to 1.28+/-0.06 ng/ml (P less than 0.0001). It appears that serotonin may be significant modulating neurotransmitter for the control of growth hormone secretion, limiting sleep-related release, and enhancing insulin-induced release. It seems likely from these data that the role of serotonin in the control of prolactin secretion is relatively more important, since serotonin receptor blockade dramatically reduced sleep-related prolactin secretion.
对10名正常青年男性每6小时服用2毫克美西麦角（一种临床使用的血清素受体阻滞剂），持续48小时。药物治疗后，睡眠期间血清生长激素水平比安慰剂值高41.9%（小于0.001）。相反，在胰岛素耐量试验期间，药物治疗使刺激的生长激素分泌减少了36.4%（P小于0.01）。美西麦角的这些相反作用表明，与睡眠相关的和胰岛素诱导的生长激素分泌的机制不同。因此，用药物刺激获得的数据可能会导致关于生理性生长激素控制机制的错误推断。服用美西麦角可显著抑制与睡眠相关的催乳素分泌；夜间催乳素总体平均值从4.30±0.19降至1.28±0.06纳克/毫升，下降了70.3%（P小于0.0001）。血清素似乎可能是控制生长激素分泌、限制与睡眠相关的释放以及增强胰岛素诱导的释放的重要调节性神经递质。从这些数据来看，血清素在控制催乳素分泌中的作用可能相对更重要，因为血清素受体阻断显著降低了与睡眠相关的催乳素分泌。
