Effects of neuropeptide Y antagonists on food intake in rats: differences with cold-adaptation.
Hyperphagia followed both central neuropeptide Y (NPY) administration and the presumed increase of endogenous NPY activity after food deprivation. NPY induced greater hyperphagia in cold-adapted than non-adapted rats; fasting of comparable severity caused similar hyperphagia in the two groups. NPY-receptor-antagonist D-Tyr(27,36), D-Thr32-NPY(27,36) or functional NPY-antagonist D-myo-inositol-1,2,6-trisphosphate attenuated the hyperphagic effect of both NPY and fasting in non-adapted rats. However, while completely preventing the NPY-hyperphagia, they did not influence the fasting-induced hyperphagia in cold-adapted rats. With cold-adaptation the sensitivity to NPY and to its antagonists increases, but the hypothalamic NPY loses from its fundamental role in the regulation of food intake, and the hyperphagia seen in cold-adaptation may need some other explanation.
Pétervári
Erika
E
Department of Pathophysiology, Faculty of Medicine, University of Pécs, 12 Szigeti út, H-7624 Pécs, Hungary.
Balaskó
Márta
M
Uzsoki
Boglárka
B
Székely
Miklós
M
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003080:Cold Temperature; D005247:Feeding Behavior / Q000187:drug effects*; D005260:Female; D005508:Food Deprivation / Q000502:physiology; D006963:Hyperphagia / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D007276:Injections, Intraventricular; D007295:Inositol Phosphates / Q000008:administration & dosage; D009478:Neuropeptide Y / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010446:Peptide Fragments / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar
D007295:Inositol Phosphates; D009478:Neuropeptide Y; D010446:Peptide Fragments; C095005:neuropeptide Y (27-36), Tyr(27,36)-Thr(32)-; C059368:atrinositol