title: Stable isotope-labeled tryptophan as a precursor for studying the disposition of quinolinic acid in rabbits.
abstract: The utility of stable isotope-labeled tryptophan as a precursor for studying the disposition of quinolinic acid was investigated. TRP-D5 at doses of 50, 25 or 10 mg/kg was administered to rabbits. Blood and CSF samples were taken for up to 6 hours. There was no loss of deuterium from the tryptophan and the specifically tri-deuterated quinolinic acid measured in plasma and CSF. CSF levels of QUIN-D3 remained elevated 6 hours following TRP-D5 administration. Further studies of the CNS disposition of quinolinic acid and other metabolites of the kynurenine pathway employing stable isotope-labeled tryptophan as precursor at appropriate doses and with extended sampling are in progress.
authors.affiliation: Laboratory of Clinical Science, NIMH, Bethesda, Maryland 20892.
authors.forename: R L
authors.initials: RL
authors.lastname: Boni
authors.forename: M P
authors.initials: MP
authors.lastname: Heyes
authors.forename: J D
authors.initials: JD
authors.lastname: Bacher
authors.forename: J A
authors.initials: JA
authors.lastname: Yergey
authors.forename: X D
authors.initials: XD
authors.lastname: Ji
authors.forename: F P
authors.initials: FP
authors.lastname: Abramson
authors.forename: S P
authors.initials: SP
authors.lastname: Markey
mesh_terms: D000818:Animals; D003903:Deuterium; D006207:Half-Life; D007737:Kynurenine / Q000378:metabolism; D008297:Male; D017378:Quinolinic Acid; D011805:Quinolinic Acids / Q000032:analysis*; D011817:Rabbits; D014018:Tissue Distribution; D014364:Tryptophan / Q000378:metabolism / Q000493:pharmacokinetics*
chemical_list: D011805:Quinolinic Acids; D007737:Kynurenine; D014364:Tryptophan; D003903:Deuterium; D017378:Quinolinic Acid