Agouti-Related Peptide, Neuropeptide Y, and Somatostatin-Producing Neurons Are Targets for Ghrelin Actions in the Rat Hypothalamus
Open Access
- 1 February 2003
- journal article
- other
- Published by The Endocrine Society in Endocrinology
- Vol. 144 (2), 544-551
- https://doi.org/10.1210/en.2002-220795
Abstract
Ghrelin, the endogenous ligand of the GH secretagogue receptor, acts at central level to elicit GH release and regulate food intake. To elucidate the neural circuit that exerts its effects, we measured the expression of hypothalamic neuropeptides involved in weight regulation and GH secretion after ghrelin administration. Adult male rats, fed or fasted for 72 h, were treated centrally (intracerebroventicularly) with a single dose of ghrelin (5 μg). After 2, 4, and 6 or 8 h, agouti-related peptide, melanin-concentrating hormone, neuropeptide Y, prepro-orexin, GHRH, and somatostatin mRNA levels were measured by in situ hybridization. We found that ghrelin increased agouti-related peptide and neuropeptide Y expression in the arcuate nucleus of the hypothalamus of fed and fasted rats. In contrast, no change was demonstrated in the mRNA levels of the other neuropeptides studied at any time evaluated. Finally, we examined the effect of ghrelin on GHRH and somatostatin mRNA levels in GH-deficient (dwarf) rats. Our results show that ghrelin increases somatostatin mRNA levels in the hypothalamus of these rats. This study furthers our understanding of the molecular basis and mechanisms involved in the effect of ghrelin on food intake and GH secretion.Keywords
This publication has 50 references indexed in Scilit:
- Intracerebroventricular Administration of Ghrelin Rapidly Suppresses Pulsatile Luteinizing Hormone Secretion in Ovariectomized RatsBiochemical and Biophysical Research Communications, 2001
- Elevated Circulating Level of Ghrelin in Cachexia Associated With Chronic Heart FailureCirculation, 2001
- Minireview: Ghrelin and the Regulation of Energy Balance—A Hypothalamic PerspectiveEndocrinology, 2001
- Regulation of PIT-1 Expression By Ghrelin and GHRP-6 Through the GH Secretagogue ReceptorMolecular Endocrinology, 2001
- Ghrelin Acts in the Central Nervous System to Stimulate Gastric Acid SecretionBiochemical and Biophysical Research Communications, 2001
- The Novel Hypothalamic Peptide Ghrelin Stimulates Food Intake and Growth Hormone SecretionEndocrinology, 2000
- Ghrelin Stimulates Gastric Acid Secretion and Motility in RatsBiochemical and Biophysical Research Communications, 2000
- Purification and Characterization of Rat des-Gln14-Ghrelin, a Second Endogenous Ligand for the Growth Hormone Secretagogue ReceptorJournal of Biological Chemistry, 2000
- Ghrelin is a growth-hormone-releasing acylated peptide from stomachNature, 1999
- Peptidomimetic Regulation of Growth Hormone SecretionEndocrine Reviews, 1997