Effects of beta-funaltrexamine on butorphanol dependence.
The present experiments were performed to investigate the effects of the selective mu opioid receptor antagonist, beta-funaltrexamine (beta-FNA), on the physical dependence liability of butorphanol (a mixed agonist/antagonist opioid analgesic). Butorphanol (26 nmol/microliter/h) was continuously infused via osmotic minipumps into the lateral cerebral ventricle of male Sprague-Dawley rats for 72 h. beta-FNA (12, 24, and 48 nmol/5 microliter/rat) was administered ICV 3 h prior to and 48 h after initiation of the butorphanol infusion. Treatment with beta-FNA significantly diminished naloxone-induced escape behavior, hypothermia, and loss of body weight in a dose-dependent manner, while naloxone-induced teeth-chattering, forepaw tremors, and urination were also reduced, but in a dose-independent manner. These results suggest that the mu opioid receptor is partially involved in the development of physical dependence upon butorphanol.
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Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson 39216.
Makimura
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Jaw
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Hoskins
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D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002077:Butorphanol / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D007276:Injections, Intraventricular; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D013375:Substance Withdrawal Syndrome / Q000523:psychology; D019966:Substance-Related Disorders / Q000517:prevention & control* / Q000523:psychology
D009292:Narcotic Antagonists; D009270:Naloxone; D009271:Naltrexone; C024524:beta-funaltrexamine; D002077:Butorphanol