title: Retention of heroin and morphine-6 beta-glucuronide analgesia in a new line of mice lacking exon 1 of MOR-1.
abstract: Morphine produces analgesia by activating mu opioid receptors encoded by the MOR-1 gene. Although morphine-6 beta-glucuronide (M6G), heroin and 6-acetylmorphine also are considered mu opioids, recent evidence suggests that they act through a distinct receptor mechanism. We examined this question in knockout mice containing disruptions of either the first or second coding exon of MOR-1. Mice homozygous for either MOR-1 mutation were insensitive to morphine. Heroin, 6-acetylmorphine and M6G still elicited analgesia in the exon-1 MOR-1 mutant, which also showed specific M6G binding, whereas M6G and 6-acetylmorphine were inactive in the exon-2 MOR-1 mutant. These results provide genetic evidence for a unique receptor site for M6G and heroin analgesia.
authors: Dept. of Neuroscience and Cell Biology, UMDNJ-Robert Wood Johnson Medical School, Piscätaway 08854, USA.
authors: A G
authors: AG
authors: Schuller
authors: M A
authors: MA
authors: King
authors: J
authors: J
authors: Zhang
authors: E
authors: E
authors: Bolan
authors: Y X
authors: YX
authors: Pan
authors: D J
authors: DJ
authors: Morgan
authors: A
authors: A
authors: Chang
authors: M E
authors: ME
authors: Czick
authors: E M
authors: EM
authors: Unterwald
authors: G W
authors: GW
authors: Pasternak
authors: J E
authors: JE
authors: Pintar
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004351:Drug Resistance / Q000235:genetics; D005091:Exons / Q000235:genetics*; D003932:Heroin / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout / Q000235:genetics / Q000502:physiology; D009022:Morphine Derivatives / Q000494:pharmacology*; D017450:Receptors, Opioid, mu / Q000235:genetics*; D014158:Transcription, Genetic / Q000502:physiology
chemical_list: D000701:Analgesics, Opioid; D009022:Morphine Derivatives; D017450:Receptors, Opioid, mu; C035349:morphine-6-glucuronide; D003932:Heroin; C026979:6-O-monoacetylmorphine