Monitoring Estra-4,9-Diene-3,17-Dione Exposure in Equine Hair

Area of Science:

• Equine Sports Medicine
• Analytical Chemistry
• Pharmacology

Background:

• Estra-4,9-diene-3,17-dione (dienedione) is a substance with potential for doping in equine sports.
• Long-term doping surveillance requires reliable methods to detect prohibited substances and their metabolites.

Purpose of the Study:

• To investigate the incorporation of dienedione and its metabolites into equine hair after administration.
• To evaluate the utility of equine hair analysis for long-term doping control.

Main Methods:

• Mane hair samples were collected from Thoroughbred horses before and after oral dienedione administration.
• Hair samples from untreated horses served as controls.
• Analysis focused on detecting dienedione and its metabolites (M3a, M7a, M7b) in hair segments.

Main Results:

• Dienedione was detected in the hair of treated horses post-administration, but not pre-administration.
• Dienedione metabolites (M3a, M7a, M7b) were also identified in the hair of treated horses.
• Segmental hair analysis revealed both systemic and external absorption routes, with interindividual variability.
• No target compounds were found in control horses' hair, despite endogenous presence in urine.

Conclusions:

• Equine hair analysis is a viable method for detecting exogenous dienedione administration.
• Hair analysis can provide definitive evidence for doping control, distinguishing exogenous administration from endogenous presence.
• This technique holds promise for long-term doping surveillance in horses.