Agouti-related protein in the hypothalamic paraventricular nucleus: effect on feeding

• Published in: Peptides (New York, N.Y. : 1980) Vol. 21; no. 9; pp. 1369 - 1375
• Main Authors: Wirth, Michelle M, Giraudo, Silvia Q
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-09-2000
• Subjects: Agouti-Related Protein; Agouti-related protein (Agrp); Animals; Darkness; Drug Interactions; Eating - drug effects; Feeding Behavior - drug effects; Food Deprivation; Food intake; Intercellular Signaling Peptides and Proteins; Light; Male; Melanocortin-4 receptor (MC4-R); Melanocortins; Neuropeptide Y - pharmacology; Paraventricular Hypothalamic Nucleus - drug effects; Paraventricular nucleus of the hypothalamus (PVN); Photoperiod; Proteins - pharmacology; Rats; Rats, Sprague-Dawley; Receptor, Melanocortin, Type 4; Receptors, Peptide - antagonists & inhibitors; Site-specific injection; Paraventricular nucleus of the hypothalamus (PVN); Site-specific injection; Melanocortin-4 receptor (MC4-R); Food intake; Rats; Melanocortins; Agouti-related protein (Agrp)
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(00)00280-1

Agouti-related protein (Agrp) is an endogenous melanocortin-4 receptor antagonist implicated in the regulation of food intake. Effects of Agrp on feeding under varying conditions were investigated. Agrp (10 to 100 pmol) was injected into the hypothalamic paraventricular nucleus of satiated (a.m. and p.m. injections) and food-deprived rats, or was co-administered with 117 pmol Neuropeptide Y (NPY). Agrp significantly stimulated light-phase feeding by 24 h post-injection. However, Agrp stimulated dark-phase and deprivation-induced feeding by 4 and 2 h, respectively. Animals receiving NPY and Agrp consumed more than animals receiving either peptide alone, the effect remaining by 24 h.