title: Effect of beta-funaltrexamine on opioid side-effects produced by morphine and U-50, 488H.
abstract: Pretreatment of rats with the irreversible mu-opioid receptor antagonist, beta-funaltrexamine (beta-FNA), 20-40 mg kg-1 s.c., produced a dose-related antagonism of the reduction in respiratory rate, gastrointestinal (GI) propulsion, rotarod reaction latencies and body temperature produced by morphine administration 24 h later, suggesting that these effects are mediated via mu-opioid receptors. The kappa-receptor agonist, U-50,488H, was without effect on respiratory rate at the doses tested, but produced hypothermia, sedation and low maximum inhibition of GI propulsion. These effects of U-50,488H were not blocked by beta-FNA suggesting that they are mediated via kappa-receptors.
authors.forename: A G
authors.initials: AG
authors.lastname: Hayes
authors.forename: M
authors.initials: M
authors.lastname: Skingle
authors.forename: M B
authors.initials: MB
authors.lastname: Tyers
mesh_terms: D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics / Q000633:toxicity*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects; D006993:Hypnotics and Sedatives; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors / Q000633:toxicity*; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D011759:Pyrrolidines / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration / Q000187:drug effects
chemical_list: D000700:Analgesics; D006993:Hypnotics and Sedatives; D009292:Narcotic Antagonists; D011759:Pyrrolidines; D009271:Naltrexone; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; C024524:beta-funaltrexamine; D009020:Morphine