title: Inhibitory effect of apelin-12 on nocturnal food intake in the rat.
abstract: Apelin, the endogenous peptide ligand of the APJ receptor, is expressed in brain regions implicated in food and water intake. This study reports for the first time, the effect of apelin-12, one of the most potent apelin peptides, on spontaneous (nocturnal) feeding. Randomised intracerebroventricular injection of 1, 3 and 10 nmol apelin-12 or saline vehicle, 10 min prior to lights out, led to dose-dependent reductions in food intake 2-4 h after injection (n = 7; p < 0.05). This suggests that apelin-12 exerts a delayed inhibitory effect on nocturnal feeding. Relative to saline, no effect was observed on total 24-h food intake post injection. In contrast, day-time administration of 10 nmol apelin-12 to satiated rats stimulated feeding (n = 5-11; p < 0.05); lower doses had no effect. No changes in water intake were observed after apelin-12. These results suggest that apelin is involved in the central control of feeding.
authors.affiliation: Department of Pharmacology, Centre for Neuroscience, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Marie
authors.initials: M
authors.lastname: O'Shea
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Hansen
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tatemoto
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Morris
mesh_terms: D000818:Animals; D000073861:Apelin; D002352:Carrier Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D002940:Circadian Rhythm; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D007276:Injections, Intraventricular; D036341:Intercellular Signaling Peptides and Proteins; D007700:Kinetics; D008297:Male; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012527:Satiation
chemical_list: D000073861:Apelin; C498579:Apln protein, rat; D002352:Carrier Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments