Food intake in rhesus monkeys following central administration of orexins

• Published in: Regulatory peptides 2005-01, Vol.124 (1), p.209-214
• Main Authors: Ramsey, Jon J., Kemnitz, Joseph W., Newton, Wendy, Hagopian, Kevork, Patterson, Terrell A., Swick, Andrew G.
• Format: Article
• Language: English
• Subjects: Animals; Appetite Depressants - administration & dosage; Appetite Depressants - pharmacology; Feeding Behavior - drug effects; Injections, Intraventricular; Intracellular Signaling Peptides and Proteins - administration & dosage; Intracellular Signaling Peptides and Proteins - pharmacology; Macaca mulatta - physiology; Male; Neuropeptide Y; Neuropeptides - administration & dosage; Neuropeptides - pharmacology; Obesity; Orexin A; Orexin B; Orexins
• ISSN: 0167-0115; 1873-1686
• DOI: 10.1016/j.regpep.2004.07.018

Orexin A has been reported to stimulate food intake in rats while orexin B does not. The purpose of this study was to determine the role of orexin A or orexin B administration on food intake in adult, male rhesus monkeys. Food intake was measured at 2 and 8 h after the morning feeding following central injections of vehicle, orexin A (10, or 20 μg) or orexin B (10, 30, or 100 μg). When compared to vehicle injections, the 10 and 20 μg doses of orexin A decreased food intake at 2 h post-dose by 45% and 64%, respectively. Eight-hour food intake was decreased at only the 20 μg orexin A dose. Orexin B at all doses and time points did not alter food intake when compared to vehicle. These results indicate that orexin A exhibits anorectic activity while orexin B does not affect food intake in the rhesus monkey.