Changes in muscle mass with mechanical load: possible cellular mechanisms.
Understanding the mechanisms that regulate skeletal muscle mass has remained a focus of numerous researchers for many years. Recent investigations have begun to elucidate cellular signaling mechanisms that regulate skeletal muscle hypertrophy, with significant effort being focused on the Akt/mammalian target of rapamycin (mTOR) signaling pathway. The Akt/mTOR pathway plays a major role in regulating the initiation of protein synthesis after the onset of mechanical loading of skeletal muscle. Although a number of downstream substrates for Akt/mTOR have been elucidated, very little is known about the upstream mechanisms that mechanical load employs to activate the Akt/mTOR signaling pathway. Thus, the purpose of this review is to discuss potential mechanisms that may contribute to the activation of the Akt/mTOR signaling mechanism in mechanically loaded skeletal muscle.
Spangenburg
Espen E
EE
University of Maryland, School of Public Health, Department of Kinesiology, College Park, MD 20742, USA. espen@umd.edu
D000222:Adaptation, Physiological; D000818:Animals; D001696:Biomechanical Phenomena; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D018482:Muscle, Skeletal / Q000166:cytology* / Q000502:physiology*; D051381:Rats; D015398:Signal Transduction / Q000502:physiology*