Effects of the selective kappa opioid antagonist, nor-binaltorphimine, on electrically-elicited feeding in the rat.
Lateral ventricular injections of the 'nonspecific' opioid antagonist naloxone (100 micrograms) and the kappa-selective opioid antagonist nor-binaltorphimine (50 micrograms) elevated the electrical brain stimulation frequency threshold for eliciting feeding behavior. Mesopontine aqueductal injections of nor-binaltorphimine, on the other hand, lowered the feeding threshold while naloxone still elevated threshold. These findings suggest the existence of forebrain kappa receptors at which endogenous opioid activity results in a facilitation of feeding while kappa receptors in the brainstem seem to mediate an inhibitory effect.
Carr
K D
KD
Department of Psychiatry, New York University School of Medicine, NY 10016.
Bak
T H
TH
Simon
E J
EJ
Portoghese
P S
PS
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004435:Eating / Q000187:drug effects*; D004558:Electric Stimulation; D007031:Hypothalamus / Q000502:physiology; D007276:Injections, Intraventricular; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D009271:Naltrexone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists; D011149:Pons / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000502:physiology*; D017473:Receptors, Opioid, kappa
D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D009270:Naloxone; C051844:norbinaltorphimine; D009271:Naltrexone