A role for neuropeptide-Y, dynorphin, and noradrenaline in the central control of food intake after food deprivation

• Published in: Endocrinology (Philadelphia) Vol. 133; no. 1; p. 29
• Main Authors: Lambert, P D, Wilding, J P, al-Dokhayel, A A, Bohuon, C, Comoy, E, Gilbey, S G, Bloom, S R
• Format: Journal Article
• Language: English
• Published: United States 01.07.1993
• Subjects: Animals; Antibodies, Monoclonal - administration & dosage; Dynorphins - physiology; Eating - drug effects; Eating - physiology; Food Deprivation - physiology; Immunization, Passive; Male; Naltrexone - analogs & derivatives; Naltrexone - pharmacology; Neuropeptide Y - immunology; Neuropeptide Y - physiology; Norepinephrine - physiology; Phentolamine - pharmacology; Rats; Rats, Wistar; Receptors, Opioid, kappa - antagonists & inhibitors
• ISSN: 0013-7227
• DOI: 10.1210/en.133.1.29

A marked increase in food intake is observed in the rat after central injection of neuropeptide-Y (NPY), dynorphin, or noradrenaline (NA). Levels of both NPY and dynorphin are increased in the hypothalamus of food-deprived rats. The aim of this study was to explore the role of NPY, dynorphin, and NA in the central control of feeding after a period of food deprivation. We have investigated the effect of intracerebroventricular injection of a monoclonal antibody to NPY (NPYAb), a potent and selective kappa-opioid receptor antagonist norbinaltorphimine (norBNI), and the alpha-adrenergic antagonist phentolamine on fast-induced food intake. In animals provided with food after a 24-h fast, NPYAb given 10 min before presentation of food reduced food intake by 30% (P < 0.01) compared to that of animals pretreated with an antibody to chloroquine. A similar (34%; P < 0.05) reduction in fast-induced feeding occurred after pretreatment with norBNI. If norBNI was given together with NPYAb, then a reduction of 51% (P < 0.05) was observed. Pretreatment with phentolamine reduced fast-induced food intake by 39% (P < 0.05), with no evidence of an additive effect when phentolamine was given together with NPYAb. These data would support a role for endogenous NPY, dynorphin, and NA in the mediation of fast-induced feeding. NPY would seem to act independently of dynorphin, but through the same mechanism as NA.