Tritos Nicholas A, Kokkotou Efi G
Department of Endocrinology, Lahey Clinic Medical Center, Burlington, MA 01805, USA.
Mayo Clin Proc. 2006 May;81(5):653-60. doi: 10.4065/81.5.653.
Ghrelin, a peptide hormone originally identified as the endogenous ligand of the growth hormone secretagogue receptor, is secreted primarily from the stomach and secondarily from the small intestine and colon. Ghrelin may also be expressed in the pancreatic islets, hypothalamus, pituitary, and several tissues in the periphery. The growth hormone secretagogue receptor is widely expressed, suggesting diverse physiologic roles for ghrelin. A growing body of evidence suggests that, in addition to its predictable effect on growth hormone secretion, ghrelin has an important role in the short-term regulation of appetite and the long-term regulation of energy balance and glucose homeostasis. Recent studies have implicated ghrelin in the regulation of gastrointestinal, cardiovascular, and immune function and have suggested a role for ghrelin in bone physiology. The identification of obestatin, a novel peptide hormone derived from the same gene as ghrelin, has recently added further complexity to ghrelin physiology. Obestatin appears to have actions opposite of ghrelin on energy homeostasis and gastrointestinal function. Despite the rapid progress, many questions remain unanswered, including the regulation of ghrelin and obestatin secretion, the downstream pathways that mediate their effects, and their precise physiologic endocrine and paracrine roles. This review presents data on ghrelin structure, expression, and function, with emphasis placed on human studies, highlighting areas that require future investigation and providing speculation about potential clinical applications of ghrelin agonists or antagonists.
胃饥饿素是一种最初被鉴定为生长激素促分泌素受体内源性配体的肽类激素，主要由胃分泌，其次由小肠和结肠分泌。胃饥饿素也可能在胰岛、下丘脑、垂体以及外周的多种组织中表达。生长激素促分泌素受体广泛表达，这表明胃饥饿素具有多种生理作用。越来越多的证据表明，除了对生长激素分泌有可预测的影响外，胃饥饿素在食欲的短期调节以及能量平衡和葡萄糖稳态的长期调节中也起着重要作用。最近的研究表明胃饥饿素参与胃肠道、心血管和免疫功能的调节，并提示其在骨骼生理学中发挥作用。一种与胃饥饿素源自同一基因的新型肽类激素——肥胖抑制素的发现，最近使胃饥饿素生理学变得更加复杂。肥胖抑制素在能量稳态和胃肠功能方面的作用似乎与胃饥饿素相反。尽管取得了快速进展，但许多问题仍未得到解答，包括胃饥饿素和肥胖抑制素分泌的调节、介导其作用的下游途径以及它们精确的生理内分泌和旁分泌作用。这篇综述介绍了有关胃饥饿素结构、表达和功能的数据，重点是人体研究，突出了需要未来研究的领域，并对胃饥饿素激动剂或拮抗剂的潜在临床应用进行了推测。
