MAITRE Arnaud ⁽¹⁾; SAUDAN Christophe ⁽¹⁾; MANGIN Patrice ⁽¹⁾; SAUGY Martial ⁽¹⁾;

⁽¹⁾Laboratoire Suisse d'Analyse du Dopage, Institut Universitaire de Medecine Legale, Rue du Bugnon 21, 1005 Lausanne, SUISSE.

Resume / Abstract

The most frequently used method to demonstrate testosterone abuse is the determination of the testosterone and epitestosterone concentration ratio (T/E ratio) in urine. Nevertheless, it is known that factors other than testosterone administration may increase the T/E ratio. In the last years, the determination of the carbon isotope ratio has proven to be the most promising method to help discriminate between naturally elevated T/E ratios and those reflecting T use. In this paper, an excretion study following oral administration of 40 mg testosterone undecanoate initially and 13 h later is presented. Four testosterone metabolites (androsterone, etiocholanolone, 5α-androstanediol, and 5β- androstanediol) together with an endogenous reference (5β-pregnanediol) were extracted from the 1312 urines and the δ¹³ C/¹²C ratio of each compound was analyzed by gas chromatography-combustion-isotope ratio mass spectrometry. The results show similar maximum δ¹³C-value variations (parts per thousand difference of δ13 C/¹² C ratio from the isotope ratio standard) for the T metabolites and concomitant changes of the T/E ratios after administration of the first and the second dose of T. Whereas the T/E ratios as well as the androsterone, etiocholanolone and 5α-androstanediol δ¹³C-values returned to the baseline 15 h after the second T administration, a decrease of the 5β- androstanediol δ-values could be detected for over 40 h. This suggests that measurements of 5β- androstanediol δ-values allow the detection of a testosterone ingestion over a longer post-administration period than other T metabolites δ C-values or than the usual T/E ratio approach.

Revue / Journal Title

Journal of analytical toxicology ISSN 0146-4760 CODEN JATOD3

Source / Source

Congres; Joint Meeting of the Society of Forensic Toxicologists and the International Association of Forensic Toxicologists , ETATS-UNIS (28/08/2004) 2004, vol. 28, n^o 6 (150 p.) [Document : 6 p.] (17 ref.), pp. 426-431 [6 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Preston, Niles, IL, ETATS-UNIS (1977) (Revue)

Mots-cles anglais / English Keywords

Urine; Combustion; Isotopic composition; Mass spectrometry; Coupled method; Gas chromatography; Human; Oral administration; Pharmacokinetics; Elimination; Biological fluid; Steroid; Androgen; Metabolite; Testosterone; Quantitative analysis; Chemical analysis;

Mots-cles frangais / French Keywords

Urine; Combustion; Composition isotopique; Spectrometrie masse; Methode couplee; Chromatographie phase gazeuse; Homme; Voie orale; Pharmacocinetique; Elimination; Liquide biologique; Steroi'de; Androgene; Metabolite; Testosterone; Analyse quantitative; Analyse chimique.

Mots-cles espagnols / Spanish Keywords

Orina; Combustion; Composicion isotopica; Espectrometna masa; Metodo acoplado; Cromatograffa fase gaseosa; Hombre; Via oral; Farmacocinetica; Eliminacion; Lfquido biologico; Esteroide; Androgeno; Metabolito; Testosterona; Analisis cuantitativo; Analisis qrnmico.

Localisation / Location

INIST-CNRS, Cote INIST : 17415, 35400011403152.0070