Metabolic studies of 1‐testosterone in horses. Issue 2 (20th June 2012)

• Record Type: Journal Article
• Authors: Kwok, W. H.; Ho, Emmie N. M.; Leung, Gary N. W.; Tang, Francis P. W.; Wan, Terence S. M.; Wong, Henry N. C.; Yeung, John H. K.
• Is Part Of: Drug testing and analysis. Volume 5:Issue 2(2013:Feb.)
• Page Start: 81
• Page End: 88
• Publication Date: 2012-06-20
• Subjects: Drugs -- Analysis -- Periodicals; Drug testing -- Periodicals; Chemistry, Forensic -- Periodicals; 615.1901
• DOI: 10.1002/dta.1380
• Languages: English
• ISSNs: 1942-7603

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>1‐Testosterone (17β‐hydroxy‐5α‐androst‐1‐en‐3‐one), a synthetic anabolic steroid, has been described as one of the most effective muscle‐building supplements currently on the market. It has an anabolic potency of 200 as compared to 26 for testosterone. Apart from its abuse in human sports, it can also be a doping agent in racehorses. Metabolic studies on 1‐testosterone have only been reported for human in the early seventies, whereas little is known about its metabolic fate in horses. This paper describes the studies of <italic>in vitro</italic> and <italic>in vivo</italic> metabolism of 1‐testosterone in horses, with the aim of identifying the most appropriate target metabolites to be monitored for controlling the misuse or abuse of 1‐testosterone in racehorses.</p> <p>Six <italic>in vitro</italic> metabolites, namely 5α‐androst‐1‐ene‐3α, 17β‐diol (T1a), 5α‐androstane‐3β, 17β‐diol (T2), epiandrosterone (T3), 16, 17‐dihydroxy‐5α‐androst‐1‐ene‐3‐one (T4 & T5), and 5α‐androst‐1‐ene‐3, 17‐dione (T6), were identified.</p> <p>For the <italic>in vivo</italic> studies, two thoroughbred geldings were each administered orally with 800 mg of 1‐testosterone by stomach tubing. The results revealed that the parent drug and eight metabolites were detected in urine. Besides the four <italic>in vitro</italic> metabolites (T1a, T2, T3, and T5), four other urinary metabolites, namely 5α‐androst‐1‐ene‐3β, 17α‐diol (T1b), 5α‐androst‐1‐ene‐3β, 17β‐diol (T1c), 5α‐androstane‐3α, 17α‐diol (T7) and 5α‐androstane‐3β, 17α‐diol (T8) were identified. This study shows that the detection of 1‐testosterone administration is best achieved by monitoring the parent drug, which could be detected for up to 30 h post‐administration. Copyright © 2012 John Wiley & Sons, Ltd.</p> </abstract>