title: Detection of methandienone (methandrostenolone) and metabolites in horse urine by gas chromatography-mass spectrometry.
abstract: The metabolic transformation of methandienone (I) in the horse was investigated. After administration of a commercial drug preparation to a female horse (0.5 mg/kg), urine samples were collected up to 96 h and processed without enzymic hydrolysis. Extraction was performed by a series of solid-liquid and liquid-liquid extractions, thus avoiding laborious purification techniques. For analysis by gas chromatography-mass spectrometry, the extracts were trimethylsilylated. Besides the parent compound I and its C-17 epimer II, three monohydroxylated metabolites were identified: 6 beta-hydroxymethandienone (III), its C-17 epimer (IV) and 16 beta-hydroxymethandienone (V). In addition, three isomers of 6 beta,16-dihydroxymethandienone (VIa-c) were discovered. Apparently, reduction of the delta 4 double bond of 16 beta-hydroxymethandienone (V) in the horse yields 16 beta,17 beta-dihydroxy-17 alpha-methyl-5 beta-androst-1-en-3-one (VII). Reduction of the isomers VIa-c results in the corresponding 6 beta,16,17-trihydroxy-17-methyl-5 beta-androst-1-en-3-ones (VIIIa-c). The data presented here suggest that screening for the isomers of VI and VIII, applying the selected-ion monitoring technique, will be the most successful way of proving methandienone administration to a horse.
authors.affiliation: Institute of Pharmacology, Toxicology and Pharmacy, University of Munich, Germany.
authors.forename: H W
authors.initials: HW
authors.lastname: Hagedorn
authors.forename: R
authors.initials: R
authors.lastname: Schulz
authors.forename: A
authors.initials: A
authors.lastname: Friedrich
mesh_terms: D000818:Animals; D001711:Biotransformation; D004300:Doping in Sports; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006736:Horses / Q000652:urine*; D008696:Methandrostenolone / Q000493:pharmacokinetics / Q000652:urine*
chemical_list: D008696:Methandrostenolone