| Theme |
The Roles of Gut Physiological Active Peptides in the Control of Nutrition and Metabolism |
| Title |
Orexigenic Peptide Ghrelin in Gut-brain Axis |
| Author |
Hajime Suzuki |
Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences / Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences |
| Author |
Akihiro Asakawa |
Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences |
| Author |
Norifumi Nakamura |
Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences |
| Author |
Akio Inui |
Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences |
| [ Summary ] |
Ghrelin, a 28-amino acid peptide, is an endogenous ligand for growth hormone secretagogue receptors. It is synthesized principally in the stomach and is released in response to fasting. Besides stimulating growth hormone secretion, studies show that ghrelin exerts a number of central and peripheral actions such as the regulation of food intake, the control of energy balance, glucose metabolism, insulin release and cardiovascular actions. The stimulation of gastric acid secretion, and motility. Its structure is related to motilin and, together, these substances represent a novel family of gut-brain regulatory peptides. Ghrelin is a complementary, yet antagonistic, signal to leptin, reflecting acute and chronic changes in energy balance. The resultant effects are mediated by hypothalamic neuropeptide Y (NPY) and the agouti-related peptide (AgRP). Ghrelin induces a fast induced pattern of gastroduodenal motility (phase III or hunger contractions). The ghrelin-NPY axis is involved in the physiological occurrence of the interdigestive phase III contractions in rodents. Recognition of the broad spectrum of biological activities associated with ghrelin continues to expand. In the future, the diverse functions of ghrelin may raise the possibility of its clinical application for a large number of pathological conditions. |