Studies related to the metabolism of anabolic steroids in the horse: the identification of some 16-oxygenated metabolites of 19-nortestosterone.

This research paper investigates how anabolic steroids, specifically 19-nortestosterone, are metabolized in thoroughbred horses by examining the types of metabolites excreted in their urine.

Study Overview

• The research aimed to examine the metabolism of 19-nortestosterone, an anabolic steroid, in thoroughbred horses. Anabolic steroids are commonly used in performance enhancing drugs.
• The investigation was conducted by administering 19-nor[4-14C]testosterone to a horse, collecting its urine, and then analyzing the metabolites found in the urine post enzyme hydrolysis using gas chromatography-mass spectrometry (GC–MS).

Findings

• Various metabolites were found in the horse’s neutral urinary extracts post 19-nortestosterone administration.
• These metabolites include 3-Hydroxyestran-17-one, 17 alpha- and 17 beta-nortestosterone, estrane-3,17-diol (two isomers), 3,16-dihydroxyestran-17-one (two isomers), 3,17-dihydroxyestran-16-one (two isomers) and estrane-3,16,17-triol.
• Isomers refer to substances that have the same molecular formula, but different physical structures and chemical properties.

Significance

• The identification of these metabolites aids in understanding how the horse’s body breaks down 19-nortestosterone.
• This information could be relevant in drug testing horses participating in racing or other sports, where the use of performance-enhancing substances is often regulated or prohibited. The presence of certain metabolites in a horse’s urine could indicate the use of anabolic steroids.
• This research might assist in standardizing drug testing procedures for horses and in studying the biological effects of anabolic steroid use in them.