title: mu Opioid receptor knockout in mice: effects on ligand-induced analgesia and morphine lethality.
abstract: The mu opioid receptor gene (MOR) was mutated in mice by a gene targeting procedure. In these MOR-knockout mice, the analgesic effects of morphine, its major metabolites, morphine-6-glucuronide (M-6-G) and morphine-6-ethereal sulfate (M-6-S), and endomorphin-2, as well as morphine-induced lethality, were drastically reduced, whereas the effects of DPDPE and U50488 remained unchanged. It is concluded that analgesic effects of mu-specific opioid ligands and acute morphine lethality are mediated by the mu receptor.
authors.affiliation: Dept. of Pharmacology, University of Minnesota Medical School, 3-249 Millard Hall, 435 Delaware St. S.E., Minneapolis, MN 55455, USA. lohxx001@maroon.tc.umn.edu
authors.forename: H H
authors.initials: HH
authors.lastname: Loh
authors.forename: H C
authors.initials: HC
authors.lastname: Liu
authors.forename: A
authors.initials: A
authors.lastname: Cavalli
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.forename: Y F
authors.initials: YF
authors.lastname: Chen
authors.forename: L N
authors.initials: LN
authors.lastname: Wei
mesh_terms: D000701:Analgesics, Opioid / Q000633:toxicity*; D000818:Animals; D005838:Genotype; D007928:Lethal Dose 50; D008024:Ligands; D051379:Mice; D018345:Mice, Knockout; D009020:Morphine / Q000633:toxicity*; D009022:Morphine Derivatives / Q000633:toxicity; D009842:Oligopeptides / Q000633:toxicity; D017450:Receptors, Opioid, mu / Q000235:genetics*
chemical_list: D000701:Analgesics, Opioid; D008024:Ligands; D009022:Morphine Derivatives; D009842:Oligopeptides; D017450:Receptors, Opioid, mu; C105294:endomorphin 2; C035349:morphine-6-glucuronide; D009020:Morphine