Identification and quantification of metabolites common to 17alpha-methyltestosterone and mestanolone in horse urine.

This research investigates the common metabolites found in horse urine after administration of two types of anabolic steroids—17alpha-methyltestosterone and mestanolone. These findings can aid in enhancing doping tests in racehorses.

Overview and Purpose of the Study

In this study, the researchers examined common metabolites found in horse urine after the administration of two structurally related anabolic steroids—17alpha-methyltestosterone (MTS) and mestanolone (MSL). These steroids are often used for performance enhancement and are commonly abused in human sports as well. The objective of the study was to identify an easily screenable target for doping tests in racehorses.

Methodology

• Urine samples were collected from horses after dosing with MTS and MSL.
• These samples were then treated to obtain different fractions of steroids—unconjugated steroid, glucuronide, and sulfate.
• The fractions were subjected to gas chromatography/mass spectrometry (GC/MS) for further examination.

Findings of the Study

• Four metabolites were detected consistently across the urine samples post-dosing by comparing them with synthesized reference standards.
• 17Alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol was primarily detected in the sulfate fractions of urine samples following the administration of the steroids.
• This specific metabolite was detected for the longest duration in the urine samples post administration of both MTS and MSL.

Conclusion of the Study

The research concluded that 17alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol serves as a highly useful screening target for doping tests of MTS and MSL in racehorses. This finding could greatly enhance the effectiveness and reliability of doping tests in the equestrian sports industry.