title: Identification and quantification of metabolites common to 17alpha-methyltestosterone and mestanolone in horse urine.
abstract: Anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, which were developed as oral formulations for therapeutic purposes, have been abused in the field of human sports. These anabolic steroids are also used to enhance racing performance in racehorses. In humans, structurally related 17alpha-methyltestosterone (MTS) and mestanolone (MSL), which are anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, have metabolites in common. The purpose of this study was to determine metabolites common to these two steroids in horses, which may serve as readily available screening targets for the doping test of these steroids in racehorses. Urine sample collected after administering MTS and MSL to horses was treated to obtain unconjugated steroid, glucuronide, and sulfate fractions. The fractions were subjected to gas chromatography/mass spectrometry (GC/MS), and 17alpha-methyl-5alpha-androstan-3beta,17beta-diol, 17alpha-hydroxymethyl-5alpha-androstan-3beta,17beta-diol, 17alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol, and 17alpha-methyl-5alpha-androstan-3beta,16alpha,17beta-triol were detected as the common metabolites by comparison with synthesized reference standards. The urinary concentrations of these metabolites after dosing were determined by GC/MS. 17Alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol was mainly detected in the sulfate fractions of urine samples after administration. This compound was consistently detected for the longest time in the urine samples after dosing with both steroids. The results suggest that 17alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol is a very useful screening target for the doping test of MTS and MSL in racehorses.
authors: Laboratory of Racing Chemistry, 1731-2 Tsuruta-machi, Utsunomiya City, Tochigi 320-0851, Japan. Electronic address: m-yamada@lrc.or.jp.
authors: Masayuki
authors: M
authors: Yamada
authors: Laboratory of Racing Chemistry, 1731-2 Tsuruta-machi, Utsunomiya City, Tochigi 320-0851, Japan.
authors: Sugako
authors: S
authors: Aramaki
authors: Laboratory of Racing Chemistry, 1731-2 Tsuruta-machi, Utsunomiya City, Tochigi 320-0851, Japan.
authors: Toshimasa
authors: T
authors: Okayasu
authors: Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
authors: Tomoo
authors: T
authors: Hosoe
authors: Laboratory of Racing Chemistry, 1731-2 Tsuruta-machi, Utsunomiya City, Tochigi 320-0851, Japan.
authors: Masahiko
authors: M
authors: Kurosawa
authors: Laboratory of Racing Chemistry, 1731-2 Tsuruta-machi, Utsunomiya City, Tochigi 320-0851, Japan.
authors: Isao
authors: I
authors: Kijima-Suda
authors: Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
authors: Koichi
authors: K
authors: Saito
authors: Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
authors: Hiroyuki
authors: H
authors: Nakazawa
mesh_terms: D045930:Anabolic Agents / Q000378:metabolism / Q000652:urine; D000818:Animals; D002138:Calibration; D013196:Dihydrotestosterone / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006736:Horses / Q000652:urine*; D008777:Methyltestosterone / Q000378:metabolism / Q000652:urine; D015394:Molecular Structure; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D045930:Anabolic Agents; D013196:Dihydrotestosterone; C008376:mestanolone; D008777:Methyltestosterone