Muscle stem cell transplants may soon be the method of choice for increasing muscle mass and strength in bodybuilders. John Hall and colleagues from the University of Washington Medical School, in a study on rats, found that transplanting muscle stem cells and small pieces of muscle to injured muscle tissue increased muscle mass, strength, and new muscle stem cell formation that lasted a lifetime in the animals. They did not note an increased incidence of cancer from the procedure.
Humans typically lose muscle mass as they age, mainly because the muscles lose the capacity to regenerate and repair. Stem cell transplants, if they work in humans, could prevent loss of muscle mass with age (i.e., sarcopenia) and prevent muscle deterioration in diseases like muscular dystrophy. Muscle stem cell transplants would have obvious applications in sports. (Science Translational Medicine, 2: 57ra83, 2010)