RESUMEN
An in vivo study was performed in order to evaluate the depletion time of stanozolol and its main metabolites using naturally incurred urine sample collected after the administration of intramuscular injections in 12 steers. A stability study was also carried out to investigate the influence of the storage period and the freeze-thaw cycles. A fast parent drug metabolization was observed, because within 6 h after drug administration, the signal of the metabolite 16ß-hydroxystanozolol was predominant. After the second drug administration, a detection window of 17 days was obtained. The stability was studied using ANOVA, in which a storage condition of -20 °C proved stable during 240 days, which was also confirmed after 5 freeze-thaw cycles.
Asunto(s)
Estanozolol , Animales , Bovinos , Cromatografía Líquida de Alta Presión , Inyecciones Intramusculares , Estanozolol/orinaRESUMEN
One of the greatest challenges in anti-doping science is the large number of substances available and the difficulty in finding the best analytical targets to detect their misuse. Therefore, metabolism studies involving prohibited substances are fundamental. However, metabolism studies in humans could face an important ethical bottleneck, especially for non-approved substances. An emerging model for metabolism assessment is the zebrafish, due to its genetic similarities with humans. In the present study, the ability of adult zebrafish to produce metabolites of sibutramine and stanozolol, substances with a well-known metabolism that are widely used as doping agents in sports, was evaluated. They represent 2 of the most abused classes of doping agents, namely, stimulants and anabolic steroids. These are classes that have been receiving attention because of the upsurge of synthetic analogues, for which the side effects in humans have not been assessed. The samples collected from the zebrafish tank water were hydrolysed, extracted by solid-phase extraction, and analysed by liquid chromatography with high resolution mass spectrometry (LC-HRMS). Adult zebrafish could produce several sibutramine and stanozolol metabolites, including demethylated, hydroxylated, dehydroxylated, and reduced derivatives, all of which have already been detected in human urine. This study demonstrates that adult zebrafish can absorb, oxidise, and excrete several metabolites in a manner similar to humans. Therefore, adult zebrafish seem to be a very promising tool to study human-like metabolism when aiming to find analytical targets for doping control. Copyright © 2017 John Wiley & Sons, Ltd.
Asunto(s)
Doping en los Deportes , Estanozolol/orina , Pez Cebra , Adulto , Animales , Cromatografía Liquida , Humanos , Hidroxilación , Extracción en Fase Sólida , Estanozolol/química , Espectrometría de Masas en TándemRESUMEN
Doping control screening based on the enhanced resolution of comprehensive two-dimensional (2D) gas chromatography hyphenated to time of flight mass spectrometer was investigated. The identification of anabolic agents (clenbuterol, norandrosterone, epimetendiol, two methyltestosterone metabolites and 3'-hydroxystanozolol) contained in a spiked urine sample (2ng/ml) was demonstrated. Special emphasis was given to 3'-hydroxystanozolol, mainly considering the difficulty in its detection. In contrast to conventional GC-MS approaches that must use single-ion monitoring, the GC x GC-TOFMS method enabled the identification of that metabolite through the deconvolution of the full mass spectrum and also resolved the co-eluted peaks of 3'-hydroxystanozolol and an endogenous component.