Nutrient Regulation of Amino Acid Transporters in Aging Human Skeletal Muscle

The goal of the research project is to determine how aging and inactivity reduce the muscle anabolic effect of nutrients and lead to muscle and functional loss. The central hypothesis is that aging reduces mTORC1 signaling and the expression of skeletal muscle amino acid transporters in response to anabolic stimulation leading to reduced muscle adaptation to increased intracellular amino acid requirements. The investigators further hypothesize that inactivity exacerbates this effect with significant muscle and functional loss, and rehabilitation restores muscle signaling, metabolism and function to baseline values.