Response of neuropeptide Y-induced feeding to mu-, delta- and kappa-opioid receptor antagonists in the neonatal chick.
It is known that opioid antagonists reduce the orexigenic effect of neropeptide Y (NPY) in mammals. We studied the effect of three opioid antagonists on NPY-induced feeding in male broiler chicks. Beta-funaltrexamine (beta-FNA), naloxonazine (NAL), ICI-174,864 (ICI) or nor-binaltorphimine (nor-BNI), antagonists of mu-, mu1-, delta- or kappa-receptors, and NPY were co-injected in chicks. Food intake was measured 30 min after treatment. Co-injection of beta-FNA or NAL was effective in reducing NPY-induced feeding, whereas ICI and nor-BNI had little effect on NPY-induced feeding. These data suggest that the mu-opioid receptor, especially the mu1-opioid has some relation to NPY-induced feeding, and implies that an endogenous ligand, such as beta-endorphin, participates in the orexigenic effect of NPY in neonatal chicks.
Dodo
Koh-Ichi
K
Laboratory of Animal Science, Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Tarumi 3-5-7 Matsuyama, Ehime 790-8566, Japan.
Izumi
Tomofumi
T
Ueda
Hiroshi
H
Bungo
Takashi
T
D000818:Animals; D000831:Animals, Newborn; D002645:Chickens / Q000502:physiology*; D005247:Feeding Behavior / Q000187:drug effects*; D008297:Male; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009478:Neuropeptide Y / Q000378:metabolism / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000378:metabolism; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors / Q000378:metabolism; D017473:Receptors, Opioid, kappa / Q000037:antagonists & inhibitors / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors / Q000378:metabolism; D001615:beta-Endorphin / Q000187:drug effects / Q000378:metabolism
D009292:Narcotic Antagonists; D009478:Neuropeptide Y; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D001615:beta-Endorphin