The detection of AICAR administration in racehorses

Summary

The use of prohibited substances in racehorses continues to be a welfare and integrity issue. The adenosine monophosphate activated protein kinase (AMPK) activator 5-amino-4-imidazolecarboxyamide ribonucleoside (AICAR) is an endogenous (i.e. naturally occurring) substance capable of enhancing physical performance, potentially without exercise. Activation of the AMPK signalling pathway can result in increased gene expression in skeletal muscle. Consequently, AICAR has been referred to as “exercise in a pill” or “exercise mimetic”. Consequently, the administration of AICAR is prohibited for equine athletes by the International Federation of Horseracing Authorities (IFHA) and Racing Australia. Notwithstanding this, the availability of non-approved forms of AICAR for misuse in equine sports remains of concern.

Due to the endogenous nature of AICAR, its mere presence in the plasma or urine of racehorses cannot constitute a doping offence. Therefore, the prevalence of AICAR needs to be quantitatively assessed for species and matrix specific thresholds to be enforced. Furthermore, the sensitivity and specificity of statistically derived thresholds need to be verified by comparison to ethically-approved in vivo administration studies for scientifically robust and legally-defensible determination of pharmacological manipulation as distinct from physiological variation.

Program

Thoroughbred Horses

Research Organisation

Racing Analytical Services Ltd

Objective Summary

As above