title: Effects of a selective kappa-opioid agonist, U-50,488H, on morphine dependence in rats.
abstract: Rats were made dependent on morphine by mixing the drug with their only source of food. Naltrexone (0.5 mg/kg) injection precipitated a syndrome of withdrawal signs including weight loss. Pretreatment with the selective kappa agonist, U-50,488H (1.0, 30.0 or 10.0 mg/kg), generally had no effects on the signs of morphine withdrawal. In other subjects, U-50,488H was repeatedly administered (1.0, 3.0 or 10.0 mg/kg per 12 h) during the development of morphine dependence. In these subjects, the course of naltrexone-precipitated withdrawal was unchanged. These results suggest that agonist activity at kappa receptors is not sufficient to alter morphine dependence or withdrawal.
authors.affiliation: Department of Pharmacology, Hoshi University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fukagawa
authors.forename: J L
authors.initials: JL
authors.lastname: Katz
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D008297:Male; D009021:Morphine Dependence / Q000503:physiopathology*; D009271:Naltrexone / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000502:physiology*; D017473:Receptors, Opioid, kappa; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology
chemical_list: D000700:Analgesics; D011759:Pyrrolidines; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D009271:Naltrexone; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer