Classification of opioids on the basis of their ability to antagonize bombesin-induced grooming in rats.
Bombesin (0.001-0.125 microgram) elicits dose-related excessive grooming when administered i.c.v. to rats. In contrast to the grooming produced by various other endogenous and exogenous agents, bombesin-induced grooming is not markedly affected by behaviorally non-depressant doses (determined by a novel method) of morphine (3 and 10 mg/kg, s.c.). The benzomorphan, ethylketocyclazocine (0.25-0.5 mg/kg, s.c.), does attenuate bombesin-induced grooming in a dose-related and stereospecific manner. In this study, we have classified 27 opioids on the basis of their ability to antagonize bombesin-induced grooming. The results of the classification indicate that a benzomorphan nucleus is required for activity in this test. Our test provides evidence that postulated benzomorphan binding sites are functionally active as pharmacologic receptors.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001839:Bombesin / Q000494:pharmacology*; D008297:Male; D009294:Narcotics / Q000145:classification / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship
D009294:Narcotics; D010455:Peptides; D001839:Bombesin