Koliaki Chrysi, Kokkinos Alexander, Tentolouris Nicholas, Katsilambros Nicholas
First Department of Propaedeutic Medicine, Laiko General Hospital, Athens University Medical School, Agiou Thoma 17, 115 27 Athens, Greece.
Int J Pept. 2010;2010. doi: 10.1155/2010/710852. Epub 2010 Feb 2.
Ghrelin is a powerful orexigenic gut hormone with growth hormone releasing activity. It plays a pivotal role for long-term energy balance and short-term food intake. It is also recognized as a potent signal for meal initiation. Ghrelin levels rise sharply before feeding onset, and are strongly suppressed by food ingestion. Postprandial ghrelin response is totally macronutrient specific in normal weight subjects, but is rather independent of macronutrient composition in obese. In rodents and lean individuals, isoenergetic meals of different macronutrient content suppress ghrelin to a variable extent. Carbohydrate appears to be the most effective macronutrient for ghrelin suppression, because of its rapid absorption and insulin-secreting effect. Protein induces prolonged ghrelin suppression and is considered to be the most satiating macronutrient. Fat, on the other hand, exhibits rather weak and insufficient ghrelin-suppressing capacity. The principal mediators involved in meal-induced ghrelin regulation are glucose, insulin, gastrointestinal hormones released in the postabsorptive phase, vagal activity, gastric emptying rate, and postprandial alterations in intestinal osmolarity.
胃饥饿素是一种具有生长激素释放活性的强大促食欲肠道激素。它在长期能量平衡和短期食物摄入中起关键作用。它也被认为是进食开始的有力信号。进食开始前胃饥饿素水平急剧上升，而食物摄入会强烈抑制其水平。在正常体重个体中，餐后胃饥饿素反应完全取决于宏量营养素种类，但在肥胖个体中则与宏量营养素组成关系不大。在啮齿动物和瘦人身上，不同宏量营养素含量的等能量餐对胃饥饿素的抑制程度各不相同。碳水化合物似乎是抑制胃饥饿素最有效的宏量营养素，因为它吸收迅速且具有胰岛素分泌作用。蛋白质会使胃饥饿素受到长时间抑制，被认为是最具饱腹感的宏量营养素。另一方面，脂肪抑制胃饥饿素的能力较弱且不足。参与进食诱导的胃饥饿素调节的主要介质包括葡萄糖、胰岛素、吸收后阶段释放的胃肠激素、迷走神经活动、胃排空率以及餐后肠道渗透压的变化。
