Published in the Aug. 15, 2002 issue of the journal Nature, findings from a multi-institutional team describe the pivotal role of a molecule called PGC-1 in transforming “fast twitch” fibers (Type II) to “slow twitch” fibers (Type I). “Fast twitch” fibers create the bulkier, strong but quickly fatigued muscles of weightlifters or sprinters. Most muscles contain a combination of the two fibers. While researchers caution they’re not promising a new athletic stamina-enhancing drug, they say it’s certainly possible that this might benefit people who are deficient in muscle fibers because of medical conditions. “PGC-1 appears to be the switch, or a major component of it, that enables your body’s muscles to adjust to the demands being put on them,” explains Dana-Farber’s Bruce M. Spiegelman, a cell biologist and the study’s senior author who is also a professor of cell biology at Harvard Medical School. “Understanding how this system works could make it possible to develop a drug to manipulate this system.” The research team included investigators from Dana-Farber, Beth Israel Deaconess Medical Center, Boston, and the University of Texas Southwestern Medical Center, Dallas. The study was funded principally by the National Institutes of Health.
Scientists discover chemical switch that determines muscle fiber type
Might some day enable physicians to give weakened patients a drug to build up muscular endurance without exercise