Ghrelin, macronutrient intake and dietary preferences in Long-Evans rats
Ghrelin, macronutrient intake and dietary preferences in Long-Evans rats
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DOI：
10.1006/bbrc.2002.6737
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发表时间：
2002-04-12
影响因子：
3.1
通讯作者：
Stricker-Krongrad, A
中科院分区：
文献类型：
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作者：
Beck, B;Musse, N;Stricker-Krongrad, A
Ghrelin是最近发现的一种肽，主要由胃产生。作为生长激素（GH）促分泌素（GHS）受体的配体，它刺激GH分泌，但也刺激摄食，并在啮齿动物中具有脂肪形成作用。虽然它的循环水平通过禁食和再喂养来调节，但其与饮食组成的关系尚不清楚。在本文中，我们测量了Long-Evans大鼠在两种不同喂养情况下的血浆ghrelin以及两种重要的激素（瘦素和胰岛素），例如，无论是强制性的饮食还是食物选择。在第一种情况下，大鼠被喂食不平衡的饮食（高碳水化合物（HC）或高脂肪（HF）饮食）14周，而在第二种情况下，它们可以在这两种饮食之间选择2周，并根据它们的脂肪或碳水化合物偏好进行选择。HF饮食14周的摄入与较低的ghrelin水平相关（与对照饮食相比为-30%; P < 0.01）。当饮食中碳水化合物的百分比增加时，这些水平增加（与对照饮食相比+26至+42%; P < 0.01或更小）。Ghrelin与血浆瘦素（r = -0.55; P < 0.003）和血糖（r = -0.58; P < 0.001）呈负相关，与体重（r = -0.63; P < 0.0001）和通过特定脂肪垫取样估计的体脂含量（r = -0.62; P < 0.0001）呈负相关。在食物选择实验中，脂肪偏好大鼠的血浆ghrelin水平低于碳水化合物偏好大鼠（-33%，P < 0.0002）。因此，Ghrelin分泌对饮食组成非常敏感。通过脂肪摄入下调其表达可能作为一种反调节机制来限制饮食诱导的肥胖症的发展。当摄入高热量饮食时，Ghrelin可能会发出信号。(C)2002 Elsevier Science（美国）。
Ghrelin is a recently discovered peptide that is primarily produced by the stomach. As a ligand of the growth hormone (GH) secretagogue (GHS) receptor, it stimulates GH secretion but it also stimulates feeding and has adipogenic effects in rodents. Although its circulating levels are modulated by fasting and refeeding, its relationship with diet composition is not known. In the present paper, we measured plasma ghrelin as well as two important hormones (leptin and insulin) in Long-Evans rats placed in two different feeding situations, e.g., either with imposed diets or with food choice. In the first case, the rats were fed unbalanced diets (either high-carbohydrate (HC) or high-fat (HF) diets) for 14 weeks, whereas in the second situation, they had the choice between these 2 diets for 2 weeks and were selected for their fat or carbohydrate preference. The intake of the HF diet for 14 weeks was associated with lower levels of ghrelin (-30% vs control diet; P < 0.01). These levels increased when the percentage of carbohydrate in the diet increased (+26 to +42% vs control diet; P < 0.01 or less). Ghrelin was inversely correlated with plasma leptin (r = -0.55; P < 0.003) and blood glucose (r = -0.58; P < 0.001) as well as with body weight (r = -0.63; P < 0.0001) and body fat content estimated by the sampling of specific fat pads (r = -0.62; P < 0.0001). In the food choice experiment, fat-preferring rats had plasma ghrelin levels lower than the carbohydrate-preferring rats (-33%; P < 0.0002). Ghrelin secretion was therefore very sensitive to the diet composition. Its down-regulation by fat ingestion might serve as a counter-regulatory mechanism to limit the development of dietary-induced adiposity. Ghrelin may signal when a high calorie diet is ingested. (C) 2002 Elsevier Science (USA).