title: Selenium metabolites in urine of cancer patients receiving L-selenomethionine at high doses.
abstract: We investigated, with quantitative HPLC/mass spectrometry, the selenium metabolites in urine from five cancer patients receiving high doses of L-selenomethionine over an extended period (2 x 4000 microg Se/day for 7 days, then 4000 microg Se/day for 21 days) as an adjunct to their normal cancer chemotherapy. Urine samples were collected at day 0 (all 5 patients), and at 2-3 additional collection times ranging from 1 to 33 days. The background selenium concentrations ranged from 12 to 55 microg Se/L and increased to 870 to 4420 microg Se/L for the five patients during the study. All five patients had appreciable levels of selenosugars in their background urine sample, and the concentrations increased dramatically after selenium intake. Trimethylselenonium ion (TMSe), on the other hand, was generally present as only a trace metabolite in background urine, and, although the concentration of TMSe increased following selenium exposure, it became a less significant proportion relative to selenosugars. These data refute the currently accepted role of TMSe as the preferred excretion metabolite when selenium exposure is high.
authors.affiliation: Institute of Chemistry-Analytical Chemistry, Karl-Franzens University Graz, Universitaetsplatz 1, 8010 Graz, Austria.
authors.forename: Doris
authors.initials: D
authors.lastname: Kuehnelt
authors.forename: Dijana
authors.initials: D
authors.lastname: Juresa
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Francesconi
authors.forename: Marwan
authors.initials: M
authors.lastname: Fakih
authors.forename: Mary E
authors.initials: ME
authors.lastname: Reid
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D006868:Hydrolysis; D007202:Indicators and Reagents; D008297:Male; D013058:Mass Spectrometry; D008872:Microwaves; D008875:Middle Aged; D009369:Neoplasms / Q000652:urine*; D012015:Reference Standards; D018036:Selenium Compounds / Q000652:urine*; D012645:Selenomethionine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D007202:Indicators and Reagents; D018036:Selenium Compounds; D012645:Selenomethionine; C003717:trimethylselenonium