Gene Doping? (Read 446 times)

Which genes could potentially be used for gene doping? Erythropoietin (EPO) Erythropoietin is a hormone produced by the kidneys that regulates the production of red blood cells. Injection of EPO increases the number of red blood cells and thus enhances oxygen-carrying capacity, making it a sort of “wonder drug” for patients with anemia, AIDS, or cancer (Longman, 2001). However, such injections of the hormone itself have relatively short-lived effects; frequent treatments are necessary to maintain the physical benefits. This conventional method of doping is believed to be in widespread use in endurance sports like cycling and long-distance running. Gene doping, i.e. injecting a synthetic version of the EPO gene as a permanent source of extra EPO, may not be too far away. Scientists have recently injected the EPO gene into leg muscles of eight rhesus monkeys, causing significantly elevated red blood cell levels within two weeks. In four of the monkeys, however, red blood cell counts soon reached dangerous levels, and the researchers had to inject blood thinners twice a month to keep the monkeys alive. In the other four monkeys, EPO and red blood cell levels began to drop dramatically because of an immune response to both the EPO produced in the muscles by the synthetic gene and the natural EPO produced in the kidneys. Consequently, these monkeys developed severe anemia and had to be euthanized. Dr. Jim Wilson, the leader of this experiment, finds it hard “to believe that any athlete would try to do this” (Zarembo, 2004). Research on the EPO gene continues, and scientists hope to be able to reproduce the effects of a natural mutation found in the family of Eero Mäntyranta, a Finnish cross-country skier who won two gold medals in the 1964 Winter Olympics. Mäntyranta’s mutation led to an excessive response to EPO, which resulted in very high levels of red blood cells (Sweeney, 2004). This high level of red blood cells and the accompanying increase in oxygen-carrying capacity helped him and several members of his family do well in endurance sports. A synthetic gene that produced the same effect would have obvious appeal to athletes and gene therapy patients alike.