Discriminative stimulus properties of morphine mediated by mu 1-opioid receptors.
The mu-opioid receptor subtypes involved in the discriminative stimulus properties of morphine were investigated in rats that had been trained to discriminate between 3.0 mg/kg morphine and saline. The discriminative stimulus properties of morphine were significantly attenuated by beta-funaltrexamine (an irreversible mu-opioid receptor antagonist: 10 and 20 mg/kg) and naloxonazine (an irreversible mu 1-opioid receptor antagonist: 20 mg/kg). These results suggest that the discriminative stimulus properties of morphine may be mediated by mu 1-opioid receptors.
Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan.
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T
Suzuki
T
T
Mori
M
M
Tsuji
M
M
Misawa
H
H
Nagase
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004193:Discrimination Learning / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000031:analogs & derivatives / Q000494:pharmacology; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors / Q000187:drug effects*
D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D017450:Receptors, Opioid, mu; D009270:Naloxone; D009271:Naltrexone; C024524:beta-funaltrexamine; D009020:Morphine; C034643:naloxonazine