Ghrelin, an endogenous ligand for the GH secretagogue receptor, was isolated from rat stomach and is involved in a novel system for regulating GH release. Although previous studies in rodents suggest that ghrelin is also involved in energy homeostasis and that ghrelin secretion is influenced by feeding, little is known about plasma ghrelin in humans. To address this issue, we studied plasma ghr...

Ghrelin is reportedly a meal-initiation signal based on observations that concentrations increase before meals coincident with rising hunger. However, evidence that ghrelin peaks vary with feeding schedules suggests that it rises in anticipation of an expected meal, rather than eliciting feeding. To explore the entrainment of ghrelin profiles, this study investigated the association between var...

After the discovery in 1996 of the GH secretagogue-receptor type-1a (GHS-R1a) as an orphan G-protein coupled receptor, many research groups attempted to identify the endogenous ligand. Finally, Kojima and colleagues successfully isolated the peptide ligand from rat stomach extracts, determined its structure, and named it ghrelin. The GHS-R1a is now accepted to be the ghrelin receptor. The exist...

Ghrelin is an orexigenic peptide hormone produced mainly by a distinct group of dispersed endocrine cells located within the gastric oxyntic mucosa. Besides secreted gene products derived from the preproghrelin gene, which include acyl-ghrelin, desacyl-ghrelin and obestatin, ghrelin cells also synthesize the secreted protein nesfatin-1. The main goal of the current study was to identify other p...

Ghrelin is known to promote neuronal defense and survival against ischemic injury by inhibiting apoptotic processes. In the present study, we investigated the role of prostate apoptosis response-4 (Par-4), a proapoptotic gene the expression of which is increased after ischemic injury, in ghrelin-mediated neuroprotection during middle cerebral artery occlusion (MCAO). Both ghrelin and des-acyl g...

Ghrelin, a gastric peptide hormone, has been reported to regulate GH secretion and energy homeostasis. Here, we examined the effect of des-acyl ghrelin driven from the fatty acid-binding protein-4 (FABP4) promoter on adiposity and glucose metabolism. A high level of expression of des-acyl ghrelin (692 +/- 293 fmol/g fat) in adipose tissue was detected in FABP4-ghrelin transgenic mice, but not i...

Ghrelin is an acylated peptide hormone secreted primarily from endocrine cells in the stomach. The major active form of ghrelin is a 28-amino acid peptide with an n-octanoyl modification at Ser(3) (n-octanoyl ghrelin), which is essential for its activity. In addition to n-octanoyl ghrelin, other forms of ghrelin peptide exist, including des-acyl ghrelin, which lacks an acyl modification, and ot...

Although ghrelin acts as a modulator of feeding behavior and energy metabolism in the central nervous system, recent studies have implicated the peripheral actions of ghrelin in reproductive tissues. Here, we investigated the expression of ghrelin and its receptor (GHS-R) in mouse oocyte and preimplantation embryos, and we examined the role of ghrelin in the regulation of early embryo developme...

We investigated the metabolic actions of ghrelin in humans by examining the effects of acute administration of acylated ghrelin, unacylated ghrelin, and the combination in eight adult-onset GH-deficient patients. We followed glucose, insulin, and free fatty acid concentrations before and after lunch and with or without the presence of GH in the circulation. We found that acylated ghrelin, which...

BACKGROUND Functional dyspepsia (FD) is one of the most common disorders of gastrointestinal (GI) diseases. However, no curable treatment is available for FD because the detailed mechanism of GI dysfunction in stressed conditions remains unclear. We aimed to clarify the association between endogenous acylated ghrelin signaling and gastric motor dysfunction and explore the possibility of a drug ...