2015•Dialnet (Universidad de la Rioja)Requires access
Enzymatic resistant glucuronoconjugated metabolites of testosterone: from their synthesis to their evaluation as alternative markers in doping control
Aristotelis Kotronoulas
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Abstract
Testosterone (T) has been traditionally the most commonly reported doping agent and the detection of its misuse remains one of the main challenges in doping control. The current steroid profile used for the detection of T should not be seen as a static tool and the inclusion of additional markers can be an efficient way to improve our screening capabilities for the detection of T administration. Under this scope, the main objective of this thesis was to evaluate the potential of two glucuronoconjugated metabolites of T, 6OH-androsterone (6OH-Andros) and 6OH-etiocholanolone (6OH-Etio), as alternative markers for the detection of T misuse. After the synthesis and characterization of the probable glucuronides, it was demonstrated, by means of mass spectrometric analysis, that the naturraly occurred glucuronides were the 3?-glucuronide-6?-hydroxyandrosterone (6OH-Andros3G) and the 3?-glucuronide-6?-hydroxyetiocholanolone (6OH-Etio3G). An LC-MS/MS method was developed and validated for the accurate quantification of the Andros3G and 6OH-Etio3G. The method also included four glucuronides of the steroid profile, namely the glucuronides of T, epitestosterone (E), androsterone (Andros) and etiocholanolone (Etio). The potential of the Andros3G and 6OH-Etio3G as markers for T misuse was first evaluated in urine samples collected after the oral administration of T. The results showed that the 6OH-Andros3G/EG, 6OH-Etio3G/EG, 6OH-Andros3G/TG and 6OH-Etio3G/TG presented detection windows (DWs) much larger than those obtained by T/E marker. The evaluation of the Andros3G and 6OH-Etio3G was extended to urine samples collected after the intramuscular administration of T to volunteers of different ethnic populations (Caucasian and Asian). In this case, the EtioG/6OH-Andros3G was the best marker for the Caucasian population volunteers and the TG/6OH-Andros3G exceeded the 15 days of detection for the Asian population volunteers. In general, the results of this thesis showed that these two metabolites have a strong potential for the screening of T exogenous administration.