Feeding responses to mu-, delta- and kappa-opioid receptor agonists in the meat-type chick.
The present study was designed to examine the effect of specific opioid agonists on feeding behavior in neonatal chicks. The food intake of broiler chicks was significantly decreased by intracerebroventricular injection of DAMGO and beta-casomorphin, micro-opioid receptor agonists, at 30-min postinjection. In contrast, both delta-opioid receptor agonists (DADLE and DPDPE) stimulated the food intake of the chick. Similar to the delta-opioid receptor agonists, food intake was elevated by the kappa-opioid receptor agonist (U-50488H and U-62066) in a dose-dependent manner. These results suggest that the endogenous opioid peptides have an important role for feeding behavior in the central nervous system of chicks.
Laboratory of Animal Science, Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan. bungo@agr.ehime-u.ac.jp
Takashi
T
Bungo
Kazuya
K
Kawamura
Tomofumi
T
Izumi
Koh-Ichi
K
Dodo
Hiroshi
H
Ueda
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer / Q000494:pharmacology; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D002645:Chickens / Q000502:physiology*; D004435:Eating / Q000187:drug effects*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D017465:Receptors, Opioid, delta / Q000819:agonists / Q000187:drug effects*; D017473:Receptors, Opioid, kappa / Q000819:agonists / Q000187:drug effects*; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000187:drug effects*
D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D016308:Enkephalin, Leucine-2-Alanine; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D020881:Enkephalin, D-Penicillamine (2,5)-