title: Detection and quantification of glucuro- and sulfoconjugated metabolites in human urine following oral administration of xenobiotic 19-norsteroids.
abstract: Recently, the endogenous origin of nandrolone (19-nortestosterone) and other 19-norsteroids has been a focus of research in the field of drug testing in sport. In the present study, we investigated metabolites conjugated to a glucuronic acid and to a sulfuric acid in urine following administration of four xenobiotic 19-norsteroids. Adult male volunteers administered a single oral dose (10 mg) of each of four 19-norsteroids. Urinary samples collected from 0 to 120 h were subjected to methanolysis and beta-glucuronidase hydrolysis and were derivatized by N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) before gas chromatography-mass spectrometry analysis. We confirmed that 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) were present in both glucuronide (g) and sulfate (s) conjugates and 19-norepiandrosterone (19-NEA) was excreted exclusively as a sulfate fraction in urine of all 19-norsteroids tested. The overall levels of the three metabolites can be ranked as follows: 19-NA(g+s)>19-NE(g+s)>19-NEA(s). The concentration profiles of these three metabolites in urine peaked between 2 to 12h post-administration and declined thereafter until approximately 72-96 h. 19-NA was most prominent throughout the first 24 h post-administration, except for a case in which an inverse relationship was found after 6h post-administration of nandrolone. Furthermore, we found that sulfate conjugates were present in both 19-NA and 19-NE metabolites in urine of all 19-norsteroids tested. The averaged total amounts of metabolites (i.e. 19-NA(s+g)+19-NE(s+g)+19-NEA(s)) excreted in urine were 38.6, 42.9, 48.3 and 21.6% for nandrolone, 19-nor-4-androsten-3,17-dione, 19-nor-4-androsten-3beta,17beta-diol and 19-nor-5-androstene-3beta,17beta-diol, respectively. Results from the excretion studies demonstrate significance of sulfate-conjugated metabolites on interpretation of misuse of the 19-norsteroids.
authors.affiliation: Institute of Pharmacology and Toxicology, Tzu Chi University, 701 Chung Yan Road, Sec. 3, Hualien 970, Taiwan. ying@mail.tcu.edu.tw
authors.forename: Y L
authors.initials: YL
authors.lastname: Tseng
authors.forename: C-Y
authors.initials: CY
authors.lastname: Sun
authors.forename: F-H
authors.initials: FH
authors.lastname: Kuo
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002138:Calibration; D004300:Doping in Sports; D004962:Estranes / Q000008:administration & dosage / Q000494:pharmacology*; D005965:Glucuronates / Q000378:metabolism / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009654:Norsteroids / Q000008:administration & dosage / Q000494:pharmacology*; D015813:Substance Abuse Detection; D013457:Sulfur Compounds / Q000378:metabolism / Q000652:urine*; D013997:Time Factors; D015262:Xenobiotics / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D004962:Estranes; D005965:Glucuronates; D009654:Norsteroids; D013457:Sulfur Compounds; D015262:Xenobiotics; C036015:19-norandrosterone