Rat muscle plasticity in response to simulated or real microgravity

Data concerning muscle plasticity in real or simulated microgravity is discussed. Possible mechanisms responsible for the muscular atrophy associated with microgravity are explored, including changes in muscle protein synthesis, fast- and slow-twitch fiber specific changes, various metabolic alterations, blood supply and other factors. The authors conclude that a combination of local and systemic factors are responsible for the observed changes in muscle physiology.