Whereas ghrelin is produced primarily in the stomach, a small amount of it is produced in pancreatic islets. Although exogenous administration of ghrelin suppresses insulin secretion in vitro or in vivo, the role of intraislet ghrelin in the regulation of insulin secretion in vivo remains unclear. To understand the physiological role of intraislet ghrelin in insulin secretion and glucose metabo...

A kind of growth hormone secretagogue (GHS), ghrelin, was first isolated from the rat stomach and plays a major role in the activation of the growth hormone secretagogue receptor 1a (GHS-R1a) resulting the release of growth hormone (GH). The preproghrelin gene is placed on chromosome 3, at locus 3p25 –2 in humans and constitutes five exons and three introns. Ghrelin is most plentifully expresse...

Evidence indicates that medial septum nicotinic receptors regulate cognitive process. Ghrelin is a gut hormone that regulates energy homeostasis. Ghrelin also is produced in brain and known to be involved in cognitive function. The purpose of the study was to evaluate the effects of medial septal injection of ghrelin on morphine-induced memory impairment in rats. Also, the possible relationship...

Ghrelin is a gastric peptide hormone, discovered as being the endogenous ligand of growth hormone secretagogue receptor. Ghrelin is a 28 amino acid peptide presenting a unique n-octanoylation modification on its serine in position 3, catalyzed by ghrelin O-acyl transferase. Ghrelin is mainly produced by a subset of stomach cells and also by the hypothalamus, the pituitary, and other tissues. Tr...

Background: Feeding behavior is regulated via a complex network which interacts through diverse signals from central and peripheral tissues. OBJECTIVES: The main purpose of the current study was to determine the role of central cannabinoidergic (CBergic) system on ghrelin-induced hypophagia in 3-h food deprived (FD3) neonatal chicken. METHODS: In experiment 1, chicks were ICV injected with cont...

Ghrelin is an orexigenic peptide synthesized mainly by stomach and hypothalamus. Ghrelin decreases secretion of thyroid hormones. Testosterone is an esteroidogenic hormone that exerts stimulatory effects on Hypothalamus-Pituitary-Thyroid (HPT) axis activity. The aim of the present study was to investigate the effect of interactions between the central injection of ghrelin and testosterone on me...

To understand the physiological role of ghrelin, it is crucial to study both the actions of ghrelin and the regulation of ghrelin secretion. Although ghrelin actions have been extensively revealed, the direct factors regulating ghrelin secretion by ghrelin-producing cells (X/A-like cells), however, is not fully understood. In this study, we examined the effects of peptide hormones and neurotran...

Leptin plays a critical role in the central regulation of bone mass. Ghrelin counteracts leptin. In this study, we investigated the effect of chronic intracerebroventricular administration of ghrelin on bone mass in Sprague-Dawley rats (1.5 μg/day for 21 days). Rats were divided into control, ghrelin ad libitum-fed (ghrelin ad lib-fed), and ghrelin pair-fed groups. Ghrelin intracerebroventricul...

Local and systemic factors have been shown to drive the growth of breast cancer cells in postmenopausal obese women, who have increased risk of estrogen receptor-positive breast cancer. Estrogens, produced locally in the breast fat by the enzyme aromatase, have an important role in promoting cancer cell proliferation. Ghrelin, a 28-amino acid peptide hormone, may also influence cancer growth. T...

Ghrelin was recently isolated from the rat stomach as an endogenous ligand for the GH secretagogue receptor. Although it is well known that a large amount of ghrelin is produced in the gastrointestinal tract, developmental changes in ghrelin mRNA expression and differentiation of ghrelin-immunopositive (ghrelin-ip) and mRNA-expressing (ghrelin-ex) cells in the stomach have not been elucidated. ...