Muscle Reacts to a Metabolic Demand for Glucose by Mobilizing Amino Acids to Support Hepatic Gluconeogenesis

Mobilization of amino acid from muscle appears to be stimu­lated largely by a relative lack of insulin; thus mobilization occurs when blood glucose concentrations are low. Amino acids mobilized from skeletal muscle come from the intracellular amino acid pool cited earlier (see Figure 32-10). However, the mobilizing reactions are complex, and the distribution of amino acids leaving the muscle does not reflect the distribution of amino acids in the intracellular pool, as explained later.