title: Buprenorphine increases intake of freely available and operant-contingent food in satiated rats.
abstract: Opiate administration increases short-term free feeding in satiated rats. The feeding effects of the mixed opioid receptor agonist/antagonist buprenorphine were examined in both free-feeding and operant chamber paradigms. Buprenorphine (0.1 and 0.3 mg/kg) produced significant increases in short-term free feeding (i.e., 4 h), an effect enhanced by repeated administration. Buprenorphine's effects on operant responding were examined in satiated rats using a fixed ratio (FR) 80 (initial pellet) FR 3 (subsequent pellets) reinforcement schedule. Buprenorphine (0.03-0.3 mg/kg) decreased latency to begin responding for food, and increased total number of pellets consumed in a 1-h session. Increases in food intake relative to control were caused by continued responding for food as sessions progressed. Naloxone suppressed both the free-feeding and operant-contingent intake induced by buprenorphine. Thus, buprenorphine increases both freely available and lever-press contingent food intake.
authors.affiliation: Research and Medicine Service, Veterans Administration Medical Center, Minneapolis, MN 55417, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Rudski
authors.forename: D
authors.initials: D
authors.lastname: Thomas
authors.forename: C J
authors.initials: CJ
authors.lastname: Billington
authors.forename: A S
authors.initials: AS
authors.lastname: Levine
mesh_terms: D000818:Animals; D002047:Buprenorphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D004435:Eating / Q000187:drug effects*; D005502:Food; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology; D012528:Satiety Response / Q000187:drug effects*
chemical_list: D009270:Naloxone; D002047:Buprenorphine