title: Morphine-6-glucuronide, a potent mu agonist.
abstract: The 3- and the 6-glucuronides of morphine have been examined in binding studies and in vivo. The 3-glucuronide had poor affinity in all binding studies whereas the 6-glucuronide potently labeled mu, but not delta or kappa receptors with affinities similar to morphine. Microinjections of the 3-glucuronide directly into the periaqueductal gray were without effect. The 6-glucuronide, on the other hand, was up to 20-fold more potent than morphine following microinjections in the same region. High doses of the 6-glucuronide produced profound seizure activity. All 6-glucuronide actions were sensitive to the opiate antagonist naloxone.
authors.affiliation: Cotzias Laboratory of Neuro-Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: G W
authors.initials: GW
authors.lastname: Pasternak
authors.forename: R J
authors.initials: RJ
authors.lastname: Bodnar
authors.forename: J A
authors.initials: JA
authors.lastname: Clark
authors.forename: C E
authors.initials: CE
authors.lastname: Inturrisi
mesh_terms: D000818:Animals; D001711:Biotransformation; D008297:Male; D008845:Microinjections; D009020:Morphine / Q000378:metabolism / Q000494:pharmacology; D009022:Morphine Derivatives / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu
chemical_list: D009022:Morphine Derivatives; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; C035349:morphine-6-glucuronide; D009020:Morphine; C018108:morphine-3-glucuronide