An analysis of normeperidine's contribution to the rate-decreasing effects of meperidine.
The effects of normeperidine (1-17.5 mg/kg) alone and in the presence of naloxone (1 and 10 mg/kg) were studied in pigeons responding under a multiple fixed-ratio 30 response, fixed-interval 5-min schedule of food presentation. Naloxone only potentiated the rate-decreasing effects of normeperidine. The effects of meperidine also were studied after pretreatment with SKF-525A (25 and 50 mg/kg), an inhibitor of drug metabolism. SKF-525A had no effects on responding when administered alone, but it potentiated the rate-decreasing effects of meperidine. It was concluded that meperidine's rate-decreasing effects cannot be due to normeperidine, the metabolite, but rather that both of these drugs have non-narcotic actions which produce decreases in schedule-controlled responding.
D000818:Animals; D010856:Columbidae; D003216:Conditioning, Operant / Q000187:drug effects*; D003640:Dealkylation; D008297:Male; D008614:Meperidine / Q000378:metabolism / Q000494:pharmacology*; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D010424:Pentobarbital / Q000494:pharmacology; D011335:Proadifen / Q000494:pharmacology; D012055:Reinforcement Schedule; D013997:Time Factors
D009270:Naloxone; D009020:Morphine; D008614:Meperidine; D011335:Proadifen; D010424:Pentobarbital