Tolle Virginie, Bassant Marie-Helene, Zizzari Philippe, Poindessous-Jazat Frederique, Tomasetto Catherine, Epelbaum Jacques, Bluet-Pajot Marie-Therese
Institut National de la Santé et de la Recherche Médicale U549, 75014 Paris, France.
Endocrinology. 2002 Apr;143(4):1353-61. doi: 10.1210/endo.143.4.8712.
Ghrelin, an endogenous ligand for the GHS receptor, stimulates GH secretion and gastrointestinal motility and has orexigenic effects. In this study, the relationships between ghrelin, GH secretion, feeding behavior, and sleep-wake patterns were investigated in adult male rats. The half-life of exogenous ghrelin (10 microg i.v.) in plasma was about 30 min. Repeated administration of ghrelin at 3- to 4-h intervals (one during lights-on and two during lights-off periods) increased GH release and feeding activity, and decreased rapid eye movement sleep duration. Endogenous plasma ghrelin levels exhibited pulsatile variations that were smaller and less regular compared with those of GH. No significant correlation between GH and ghrelin circulating levels was found, although mean interpeak intervals and pulse frequencies were close for the two hormones. In contrast, ghrelin pulse variations were correlated with food intake episodes in the lights off period, and plasma ghrelin concentrations decreased by 26% in the 20 min following the end of the food intake periods. A positive correlation between ghrelin levels and active wake was found during the first 3 h of the dark period only. In conclusion, ghrelin, in addition to affecting GH secretion, gastrointestinal motility, and feeding activity, also modifies sleep-wake patterns. However, a direct action of ghrelin per se or the indirect effects of feeding (and all of its attendant metabolic sequelae) on sleep cannot be differentiated. Moreover, ghrelin secretion is pulsatile and directly related to feeding behavior only.
胃饥饿素是生长激素促分泌素受体的内源性配体，可刺激生长激素分泌、促进胃肠蠕动并具有促食欲作用。在本研究中，我们探讨了成年雄性大鼠体内胃饥饿素、生长激素分泌、摄食行为及睡眠-觉醒模式之间的关系。外源性胃饥饿素（静脉注射10微克）在血浆中的半衰期约为30分钟。以3至4小时的间隔重复注射胃饥饿素（光照期注射1次，熄灯期注射2次）可增加生长激素释放和摄食活动，并缩短快速眼动睡眠时长。内源性血浆胃饥饿素水平呈现出搏动性变化，与生长激素相比，其变化幅度较小且规律性较差。尽管两种激素的平均峰间间隔和脉冲频率相近，但未发现生长激素与循环中的胃饥饿素水平之间存在显著相关性。相反，胃饥饿素脉冲变化与熄灯期的进食次数相关，进食结束后20分钟内血浆胃饥饿素浓度下降了26%。仅在黑暗期的前3小时发现胃饥饿素水平与主动觉醒呈正相关。总之，胃饥饿素除了影响生长激素分泌、胃肠蠕动和摄食活动外，还会改变睡眠-觉醒模式。然而，无法区分胃饥饿素本身的直接作用或进食（及其所有伴随的代谢后果）对睡眠的间接影响。此外，胃饥饿素分泌呈搏动性，且仅与摄食行为直接相关。
