Endogenous circulating ghrelin does not mediate growth hormone rhythmicity or response to fasting
Endogenous circulating ghrelin does not mediate growth hormone rhythmicity or response to fasting
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DOI：
10.1210/jc.2004-1785
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发表时间：
2005-05-01
影响因子：
5.8
通讯作者：
Barkan, AL
中科院分区：
文献类型：
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作者：
Avram, AM;Jaffe, CA;Barkan, AL
人的GH分泌曲线是脉动的，并且在睡眠早期表现出夜间升高。禁食增加GH输出和节律性。Ghrelin被认为表现出夜间增加，并在营养缺乏时上升。我们研究了生长激素释放肽是否可能是GH节律性和对禁食反应的潜在机制。我们研究了9名年轻的健康受试者在正常喂养和完全禁食2天后。每10分钟测量一次血浆GH，每20分钟测量一次血浆总生长激素释放肽和活性生长激素释放肽。空腹增加平均每日血浆GH（1.47 +/- 0.25 vs. 3.30 +/- 0.6 μ g/L; P = 0.012）。禁食后，平均每日总生长素释放肽（4.19 +/- 0.64 vs. 4.35 +/- 0.74 μ g/L; P = 0.75）和平均每日活性生长素释放肽（0.13 +/-0.02 vs. 0.13 +/- 0.02 μ g/L; P = 0.34）均未发生变化。所有受试者均表现出夜间GH分泌增加;总生长激素释放肽或活性生长激素释放肽浓度均无相应的夜间增加。同样，交叉相关分析未能发现GH和ghrelin脉冲之间的任何关系。我们的结论是，生长激素释放肽是不太可能是重要的，在产生的节奏或营养介导的生长激素分泌。
GH secretory profiles in humans are pulsatile and exhibit nocturnal elevation during the early hours of sleep. Fasting augments GH output and rhythmicity. Ghrelin was suggested to exhibit nocturnal increases and to rise in response to nutritional deprivation. We examined whether ghrelin may be an underlying mechanism of GH rhythmicity and response to fasting. We studied nine young healthy subjects during normal feeding and after 2 d of complete fasting. Plasma GH was measured every 10 min, and plasma total and active ghrelins were measured every 20 min. Fasting augmented mean daily plasma GH(1.47 +/- 0.25 vs. 3.30 +/- 0.6 mu g/liter; P = 0.012). Neither mean daily total ghrelin (4.19 +/- 0.64 vs. 4.35 +/- 0.74 mu g/liter; P = 0.75) nor mean daily active ghrelin (0.13 +/- 0.02 vs. 0.13 +/- 0.02 mu g/liter; P = 0.34) changed as a result of fasting. All subjects exhibited nocturnal augmentation of GH secretion; there were no corresponding nocturnal increases in either total or active ghrelin concentrations. Similarly, cross-correlation analysis failed to find any relation between GH and ghrelin pulses. We conclude that ghrelin is unlikely to be of importance in the generation of rhythmic or nutritionally mediated GH secretion.