Comparison of morphine, meperidine, anileridine, and alphaprodine on schedule-controlled responding and analgesia.
The effects of morphine, meperidine, alphaprodine, and anileridine were studied alone and in the presence of 1 mg/kg of naloxone in rats on level pressing under a fixed-ratio 20-response schedule of food presentation and on tail-withdrawal latency from warm water (55 degrees C) as a measure of analgesia. All four narcotics decreased rates of lever pressing and increased tail-withdrawal latencies. Naloxone antagonized the effects of all four narcotics on tail-withdrawal, but did not antagonize the rate-decreasing effect of meperidine on lever pressing. Naloxone shifted the morphine dose-effect for lever-pressing by a factor of 4-8; the alphaprodine dose-effect curve by a factor of 4-8; and the anileridine dose-effect curve by a factor of 2. These results strengthen the interpretation that meperidine's effect on schedule-controlled responding is not mediated by a narcotic action whereas the analgesic effect is. The results also suggest that anileridine has significant non-narcotic actions like meperidine.
D000522:Alphaprodine / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D007540:Isonipecotic Acids / Q000494:pharmacology; D008297:Male; D008614:Meperidine / Q000494:pharmacology; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D012055:Reinforcement Schedule
D000701:Analgesics, Opioid; D007540:Isonipecotic Acids; D000522:Alphaprodine; D009270:Naloxone; C100232:anileridine; D009020:Morphine; D008614:Meperidine