Inhibitory effect of apelin-12 on nocturnal food intake in the rat.
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.
O'Shea
Marie
M
Department of Pharmacology, Centre for Neuroscience, The University of Melbourne, Victoria 3010, Australia.
Hansen
Michelle J
MJ
Tatemoto
Kazuhiko
K
Morris
Margaret J
MJ
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
D000073861:Apelin; C498579:Apln protein, rat; D002352:Carrier Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments