Späth-Schwalbe E, Hundenborn C, Kern W, Fehm H L, Born J
Department of Clinical Neuroendocrinology, University of Luebeck, Germany.
J Clin Endocrinol Metab. 1995 Jan;80(1):214-9. doi: 10.1210/jcem.80.1.7829614.
Recent studies have suggested that spontaneous release of GH as well as GH secretion stimulated by exogenous GHRH are influenced by central nervous mechanisms that regulate sleep and wakefulness. Here, the effect of nocturnal wakefulness on GH secretion stimulated by i.v. administration of GHRH was examined in two experiments in healthy men. On all nights, GHRH (1 microgram/kg BW) was injected after the subjects had slept for about 2.5 h to minimize interference of endogenous release of GH during early sleep with the response to exogenous GHRH. Both experiments included a control condition to assess GH secretory responses to GHRH during undisturbed sleep and an experimental condition to assess the effect of wakefulness. In the control conditions, subjects slept throughout the night, and GHRH was administered 170 min after sleep onset. In the experimental condition of Exp I (n = 10), subjects were awakened 150 min after sleep onset and stayed awake. GHRH was given 20 min after awakening. In the experimental condition of Exp II (n = 8), subjects were awakened 30 min after GHRH treatment, which was administered 170 min after sleep onset. GHRH administrations during sleep fell into epochs of stage 2 sleep or rapid eye movement sleep. GH secretion and sleep characteristics before GHRH administrations were comparable for experimental and control conditions of both experiments. GH secretory responses were inhibited when the subject was awake at the time of GHRH administration compared to GH responses during undisturbed sleep. Awakening the subject 30 min after GHRH administration abruptly interrupted the initiated GH secretory response. The results demonstrate a profound inhibitory effect of nocturnal awakenings on GHRH-induced GH secretion. They indicate that the GH secretory response to GHRH is strongly determined by central nervous system sleep-wake activity.
最近的研究表明，生长激素（GH）的自发释放以及外源性生长激素释放激素（GHRH）刺激的GH分泌受调节睡眠和觉醒的中枢神经机制影响。在此，在两项针对健康男性的实验中，研究了夜间觉醒对静脉注射GHRH刺激的GH分泌的影响。在所有夜晚，在受试者睡眠约2.5小时后注射GHRH（1微克/千克体重），以尽量减少早期睡眠期间内源性GH释放对对外源性GHRH反应的干扰。两项实验均包括一个对照条件，以评估在不受干扰的睡眠期间对GHRH的GH分泌反应，以及一个实验条件，以评估觉醒的影响。在对照条件下，受试者整夜睡眠，在睡眠开始后170分钟给予GHRH。在实验一（n = 10）的实验条件下，受试者在睡眠开始后150分钟被唤醒并保持清醒。唤醒后20分钟给予GHRH。在实验二（n = 8）的实验条件下，在GHRH治疗后30分钟唤醒受试者，GHRH在睡眠开始后170分钟给予。睡眠期间的GHRH给药处于睡眠2期或快速眼动睡眠阶段。两项实验的实验条件和对照条件下，给药前的GH分泌和睡眠特征具有可比性。与不受干扰的睡眠期间的GH反应相比，当受试者在给予GHRH时处于清醒状态时，GH分泌反应受到抑制。在GHRH给药后30分钟唤醒受试者会突然中断已启动的GH分泌反应。结果表明夜间觉醒对GHRH诱导的GH分泌有深远的抑制作用。它们表明，对GHRH的GH分泌反应强烈受中枢神经系统睡眠-觉醒活动的决定。
