Regrowth of skeletal muscle atrophied from inactivity.

The current state of knowledge regarding regrowth of skeletal muscle after inactivity-induced atrophy is reviewed. Muscle regrowth is incomplete after hindlimb suspension in juvenile rats and after limb immobilization in old animals. The process of regrowth from immobilization-induced atrophy likely involves the reversal of directional changes in molecules producing muscle loss while initiating anabolic processes for regrowth of muscle mass. Unfortunately, the molecular mechanisms responsible for successful, or failed, muscle regrowth are not well understood. The purpose of the review is to provide current knowledge about the biology of muscle regrowth from inactivity-induced atrophy.