Rhythms of ghrelin, leptin, and sleep in rats: effects of the normal diurnal cycle, restricted feeding, and sleep deprivation
Rhythms of ghrelin, leptin, and sleep in rats: effects of the normal diurnal cycle, restricted feeding, and sleep deprivation
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DOI：
10.1152/ajpregu.00294.2004
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发表时间：
2004-11-01
影响因子：
2.8
通讯作者：
Krueger, JM
中科院分区：
文献类型：
--
作者：
Bodosi, B;Gardi, J;Krueger, JM
为了确定血浆ghrelin和leptin浓度和下丘脑ghrelin含量与睡眠、大脑皮层温度（T-crt）和进食之间的关系，我们在三种实验条件下测定了大鼠的这些参数：在具有正常昼夜节律的自由进食大鼠中，在进食限制于12小时光照期（RF）的大鼠中，以及在光周期开始时经历5小时睡眠剥夺（SD）的大鼠中。血浆ghrelin和leptin显示昼夜节律，ghrelin峰值在黑暗开始后1小时的主要日摄食峰值之前，leptin峰值在黑暗开始后1小时的主要日摄食峰值之后。RF逆转了这些激素的昼夜节律和快速眼动睡眠（REMS）的节律，并显著改变了T-crt的节律。与此相反，非快速眼动睡眠（NREMS）的持续时间和强度对射频几乎没有反应。SD未能改变瘦素浓度，但它迅速刺激血浆ghrelin和诱导进食。SD引起下丘脑ghrelin含量的双相变化。SD增加血浆皮质酮，但皮质酮似乎没有影响瘦素或ghrelin。结果表明，喂养和瘦素的昼夜节律之间有很强的关系，喂养也从根本上调节生长激素释放肽的昼夜节律。下丘脑生长激素释放肽含量的变化可能与大鼠的睡眠-觉醒活动有关，但是，与以前在人类中的观察不同，在大鼠的睡眠和血浆生长激素释放肽或瘦素浓度的昼夜节律之间不能检测到明显的联系。
To determine the relationships among plasma ghrelin and leptin concentrations and hypothalamic ghrelin contents, and sleep, cortical brain temperature (T-crt), and feeding, we determined these parameters in rats in three experimental conditions: in free-feeding rats with normal diurnal rhythms, in rats with feeding restricted to the 12-h light period (RF), and in rats subjected to 5-h of sleep deprivation (SD) at the beginning of the light cycle. Plasma ghrelin and leptin displayed diurnal rhythms with the ghrelin peak preceding and the leptin peak following the major daily feeding peak in hour 1 after dark onset. RF reversed the diurnal rhythm of these hormones and the rhythm of rapid-eye-movement sleep (REMS) and significantly altered the rhythm of T-crt. In contrast, the duration and intensity of non-REMS (NREMS) were hardly responsive to RF. SD failed to change leptin concentrations, but it promptly stimulated plasma ghrelin and induced eating. SD elicited biphasic variations in the hypothalamic ghrelin contents. SD increased plasma corticosterone, but corticosterone did not seem to influence either leptin or ghrelin. The results suggest a strong relationship between feeding and the diurnal rhythm of leptin and that feeding also fundamentally modulates the diurnal rhythm of ghrelin. The variations in hypothalamic ghrelin contents might be associated with sleep-wake activity in rats, but, unlike the previous observations in humans, obvious links could not be detected between sleep and the diurnal rhythms of plasma concentrations of either ghrelin or leptin in the rat.