| Outsmarting the Cheats |
| Tuesday, 11 January 2005 | |
|
Mushrooms, plant seeds, dried figs and dogs' testicles might not
appear to have much in common. Yet for Greek Olympians 2000 years ago,
these were the equivalent of doping. Times have changed though, and in
what has become a highly lucrative business, the methods and drugs
available to enhance athletic performance are becoming increasingly
sophisticated. The scandals of Athens may have left the front pages,
but the problem remains. Modern day cheats have tricks up their
sleeves, but scientists are working hard to find methods to catch them
out. Will they have outsmarted the cheats by the time the Olympics
reach Beijing in 2008?
These ‘designer' drugs are either almost identical to those naturally
produced by our body, making it impossible to detect them as synthetic,
or are so recently developed that they are virtually unheard of in the
scientific community. Scientists at the World Anti-Doping Agency (WADA)
are faced with the challenging task of developing tests to detect
chemicals which either appear to be invisible or they don't even know
exist! "Urine is currently the main matrix we use for drug testing, but
blood will be increasingly used as we develop tests for previously
undetectable substances. Hair, saliva and sweat detection methods are
being considered for future use," explains Dr Olivier Rabin, Scientific
Director for WADA.
The main area of research at present is the development of a reliable
test for HGH, but it's not an easy task as Dr Richard Holt, Head of the
Growth Hormone 2004 project, discovered: "The first problem we came up
against was that HGH isn't excreted in our urine, so we couldn't use
urine testing. Secondly, HGH is secreted in pulses, meaning that levels
within the body can vary tremendously. Thirdly, both stress and
exercise increase HGH levels, so you can imagine that during a major
competition, an athlete's HGH will naturally increase. Finally HGH that
the cheats administer is identical to naturally produced growth
hormone. All this makes our job of finding an accurate test very
difficult indeed."
To date, two approaches have been followed to detect exogenous growth
hormone: the isoform method and the downstream markers method. The
isoform method relies upon the fact that our body naturally produces
many molecules of growth hormone, which vary in weight. These are known
as isoforms, and the naturally predominant one weighs 22 kiloDaltons
(kDa). The injected form of HGH consists purely of the 22 kDa form, and
causes all the other isoforms to disappear from the circulation. Thus,
by looking at the ratio of the different isoforms, the presence of
exogenous HGH can be detected. Unfortunately, this method only detects
HGH injected up to 24 hours before, a risk very few athletes are
willing to take. Instead, they are more likely to take HGH in training
several weeks before competition.
Dr Holt's research group has been pioneering the downstream markers
approach. Unlike the isoform method, this test looks at the secondary
effects of HGH on the body, and is concerned with the stimulation of
protein production, particularly IGF-1 and procollagen type 3. The
fundamental principle behind the test is that subjects injecting
exogenous HGH will have unusually high concentrations of these two
markers. "The beauty of this method is that although it takes longer
for these markers to rise, it also takes longer for them to fall. So we
have a greater chance of catching the cheats," says Dr Holt.
This research is encouraging but Dr Holt and his colleagues at WADA may
soon face another hurdle: gene doping, the altering of an individual's
genetic make up to gain genes that will ultimately enhance their
performance. Gene doping can be achieved in two ways: either by
directly injecting the gene into the muscle or tissue, or by delivering
it to all the tissues via a virus. Although talk of gene doping may
conjure images of ‘super-humans', and the topic is often treated as
futuristic, there is no escaping the fact that mice and baboons have
already proved successful subjects for gene therapy. So, just how
ridiculous is the idea that athletes might use it? "Sadly, gene doping
is a real possibility," sighs Dr Richard Budgett, Director of Medical
Services at the British Olympic Association. "Therapeutic genetic
treatments are rapidly improving, which is great. Unfortunately there's
very little to stop someone injecting a gene for EPO instead." Emma McIlroy is a third year Natural Scientist specialising in Experimental Psychology |
Among the most popular performance enhancing drugs are peptide
hormones, including erythropoietin (EPO), human growth hormone (HGH)
and insulin-like growth factor 1 (IGF-1). These are all naturally made
by the body, but cheats inject an almost identical synthetic form,
which augments the body's natural levels and potentiates their effects.
EPO is naturally produced by the kidneys and stimulates erythropoiesis;
the production of red blood cells. By injecting EPO, athletes can
increase their red blood cell count and thus improve their ability to
carry oxygen, which is an attractive prospect in endurance events. HGH
is naturally produced in the brain by the pituitary gland, and
stimulates the growth of muscle, cartilage, and bone. Cheats commonly
use it to increase muscle size and reduce muscle fatigue. Of course,
all this doesn't come without a price. Aside from the prospect of a
lifetime ban, there are plenty of downsides to doping. HGH, for
example, can cause heart, liver and kidney damage, various cancers and
abnormal growth of the hands and face. These are the hard-hitting
consequences, which are often forgotten in the pursuit of glory.| < Prev | Next > |
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