Behavioral effects of MK-801 in morphine-dependent and non-dependent mice.
The behavioral effects of MK-801 were compared in morphine-dependent and non-dependent mice. The dose of MK-801 selected for these studies was previously demonstrated to attenuate some of the morphine withdrawal signs. Subjects were repeatedly exposed to morphine (8 days, b.i.d., 10-100 mg/kg, s.c.). Twenty-four hours after last morphine injection mice received naloxone (0.1 mg/kg, s.c.) and the observation was commenced. Animals were pretreated with either MK-801 (0.1 mg/kg, i.p.) or saline 30 min prior to testing. It was found that the behavioral effects of MK-801 (decreased sociability, and increased rate of transitions between behavioral elements, locomotion, grooming) were less pronounced in morphine-dependent compared to non-dependent subjects. However, the intensified almost stereotypic eating possibly reflected increased psychotomimetic potency of MK-801 in morphine-withdrawn animals.
Department of Pharmacology, Pavlov Medical University, St.-Petersburg, Russia.
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Belozertseva
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Zvartau
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Bespalov
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence / Q000503:physiopathology*; D009043:Motor Activity / Q000187:drug effects; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology
D000701:Analgesics, Opioid; D018691:Excitatory Amino Acid Antagonists; D009292:Narcotic Antagonists; D009270:Naloxone; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D009020:Morphine