CAPSAICIN, the drug at the centre of yesterday's equine testing controversy in Beijing, is the compound that is responsible for chilli peppers feeling hot on the tongue, lips and skin. It is classified as a class 'A' substance and is on the International Olympic Committee's banned list.
The drug, administered externally, has been used on horses for its pain relieving properties. Studies have shown that when capsaicin is applied to an area of the body, it depletes a neurotransmitter called "substance P", which relays pain signals from an injured site to the brain. It has been used in treating lameness in horses and also for hyper-sensitising the skin.
The more sinister use is the latter - as the horse is likely to lift higher during jumping so as not to hit the sensitised area of its leg.
Like the sedatives, fluphenizine and zuclopenthixol, found in the system of Cian O'Connor's horse Waterford Crystal during the Athens Games in 2004, capsaicin is also used for the treatment of humans with osteoarthritis, herpes illnesses such as shingles, and diabetes.
In previous Olympic Games, however, the drug would not have been detected until weeks after the event. For the Beijing Games the laboratory used for the testing of samples was on site at the Hong Kong Jockey Club.
It is only one of four laboratories in the world recognised by the International Equestrian Federation for such testing and because of its proximity to the equestrian event, it was able to turn around the samples in just four days.
The blood and urine samples from all four of the banned horses were taken on Monday and the results were known yesterday.
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