SUPPRESSION OF NOCTURNAL, PALATABLE AND GLUCOPRIVIC INTAKE IN RATS BY THE KAPPA-OPIOID ANTAGONIST, NOR-BINALTORPHAMINE

The increased food intake in the rat during the first two hours of the dark cycle was significantly inhibited by central pretreatment with either the selective κ opioid antagonist, nor-binaltorphamine (NorBNI, 20 μg, i.c.v., 53-54%) or naltrexone (NTX, 20 μg, i.c.v., 47-60%). Short-term (2 h) intake of a high-fat diet was significantly inhibited by central NorBNI (1-20 μg, 33-79%) and NTX (20 μg, 47-51%). Hyperphagia induced by the anti-metabolic glucose analogue, 2-deoxy-d-glucose was significantly inhibited by central NorBNI (20 μg, 40-68%) and NTX (20 μg, 28-69%). These data suggest that the κ receptor subtype, in addition to other opioid receptor subtypes, influence these forms of feeding behavior. © 1990.