Friday, June 14, 2013

Beaver Doping: How Myoglobin Alteration Will Change Cycling

EPO has taught us all about hemoglobin, that epicenter of the current doping war, but the next wave of doping could be fought over enhancements to its lesser-known partner in oxygen carrying, myoglobin.

Hemoglobin, as we all know, is a protein in our red blood cells that carries oxygen.  Having more hemoglobin means the blood carries more oxygen as it circulates from the heart to the lungs through the vascular system.

Taking EPO or a blood transfusion increases hemoglobin, making it thicker.  Having blood as thick as pudding--having a high ratio of red blood cells to plasma (i.e., having a high hematocrit) can help you climb mountains, but it can also kill you.

Hemoglobin is far from simple.  Infants are born with a type that disappears as they develop another.  Sickle cell anemia is caused by a type of hemoglobin (one that resists the effects of malaria), as is thalassemia--a disease of anemia that originated in peoples of the Mediterranean. 

Having the wrong kinds of hemoglobin can be deadly, but so can simply having too much or too little.  Among the things that can cause excess hemoglobin are prolonged exposure to high altitude, dehydration, tumors, smoking, and, of course, EPO.

Hemoglobin in Type II diabetics has more of a tendency to bind with glucose.  This may sound like a good thing, carrying energy through the body, but it isn't--the blood is carrying glucose instead of oxygen, and that can lead to hypoxia.  

What hemoglobin is to the vascular system, myoglobin is to the muscular system--it carries oxygen through the muscles. While arteries carry oxygenated blood from the heart and lungs to the muscle exterior, myoglobin carries oxygen to the muscles themselves.

Myoglobin is extensively studied, but it is still something of a mystery.  For instance, mice engineered without it functioned normally; their vascular systems compensated.

If you've ever wondered how beavers (and other sea mammals) can hold their breaths so long, myoglobin is your answer.  The muscles of animals that have to function with little oxygen--whales, beaver, seals, and moles--have higher concentrations of myoglobin than us land mammals, allowing them to distribute and use oxygen more efficiently, as you might expect.  

There are limits to myoglobin concentration in land mammals, since, as with hemoglobin, if it reaches certain concentrations it bunches up and clots.  Myoglobin in marine mammals, a recent study found, evolved to be less sticky ("an adoptive structure of elevated myoglobin net surface charge") and therefore allowing much higher concentrations than in land mammals.  

The study goes on to predict the dive times of animals, living and extinct, based on the results of their findings and the context of evolution--specifically, they identified the "land-to-water" transition as when the myoglobin of sea mammals became less sticky, enabling mammals to submerge for longer and longer periods.


This puts a twist on the popular representation of evolution, which puts evolution as a process coming out of the water, rather than into it.

At some point, then, life moved from the sea to land, but it also then moved back into it.  Whales, dolphins, seals, and beavers--these creatures evolved from ancient landlubbers, who had evolved from even more ancient sea dwellers.

Non-sticky and concentrated myoglobin, along with flippers, blubber, and blowholes, is one of the products of this circuitous evolution.  It allows northern bottlenose whales, for instance, to submerge two hours without breathing.

Just last year, scientists announced the invention of a shot to temporarily sustain life in those who cannot breath. The injection carries oxygen directly to the bloodstream, bypassing the lungs.  

How long before the next Di Luca starts shooting up with oxygen at the start of Zoncolan?

Even more radical?  Replacing one's myoglobin with the myoglobin of sperm whales, with drugs or genetic tinkering, making it less sticky and more prevalent.   

Humans portray ourselves as more evolved (cthulu excepted) than other species, but all living animals are equally evolved, since we have all evolved over the same period of time and from that first life.        

We're at a time where evolution is, for the first time, intentional.  We can alter our genes and we can supplement our capabilities with machines.  

If we do begin to alter ourselves, I suppose there are two possibilities:  we either treat our bodies as machines or we discard our bodies in favor of machines. 

Can you imagine scuba diving with no gear?  Instead, you'd simply need a small device injecting oxygen directly into your blood.  Or you'd simply alter your myoglobin, and only need to bother with taking a breath every 30 minutes.

Yeah, yeah.  No one cares about this kind of stuff, even if it comes around in the next few years when you and I are still alive.  What we care about is bike racing!  

Myoglobin Doping and the Future of Bike Racing  
At some point, we may be able to splice the genes of sea mammals that structure myoglobin protein into our own.  Breathing, at that point, will be something we "used to do."  And this, I need hardly point out, will change bike racing.  We'll forget what it felt like to asphyxiate ourselves on a steep climb, climbing upwards into the thinnest of air with a smile, oxygen flowing through our muscles like, well, a beaver.