Doping control study of AICAR in post-race urine and plasma samples from horses.

The study focuses on controlling the deliberate use of AICAR, a natural AMPK activator, in racehorses. The researchers conducted tests on post-race equine urine and plasma samples from different countries and proposed a screening cut-off in the urine to detect AICAR.

Objective of the Study

• The study was primarily focused on controlling the intentional use of AICAR (Acadesine), an activator for adenosine monophosphate-activated protein kinase (AMPK) naturally occurring in mammals like humans and horses. Being classified by the World Anti-Doping Agency (WADA) as gene doping, it has gained attention as it enhances performance endurance, earning it the term ‘exercise pill’.

Methodology

• Researchers collected and analyzed 1,470 post-race equine urine samples from thoroughbreds and standardbreds in Australia, France, and Hong Kong.
• They developed quantification methods in equine urine and plasma using liquid chromatography-mass spectrometry.
• They exchanged spiked urine and plasma samples among the three countries, validating there were no significant differences in the methods.

Findings

• The research team noted a rise in AICAR concentration in plasma when whole blood samples underwent haemolysis, making it challenging to establish a suitable threshold in horses’ plasma for AICAR detection.
• They suggested a possible urine screening cut-off for racehorses at 600 ng/mL for AICAR control.
• The proposed urine screening cut-off was applied to samples obtained post-intravenous administering of a small AICAR dose (2 g) to a mare, which gave a detection period of approximately 4.5 hours.

Significance of the Study

• The study has significance due to its potential in controlling deliberate AICAR administration in racehorses, as the substance is known to artificially enhance their endurance performance, providing an unfair advantage.
• The detection protocol for AICAR proposed by the study has importance in the context of regulatory measures for fair participation in equine sports and welfare of the animals.