ABSTRACT
Glutamine production and release appears to be coordinated with alanine production and release in the skeletal muscle. In an accelerated proteolytic state, increases in cyclic nucleotides, responding to changes in circulating hormone levels, cause a decrease in glutamine release. The skeletal muscle is the site of greatest amino acid production and release. Amino acids, principally alanine and glutamine, are the most important sources for de novo carbon for the production of glucose. Control of the processes of synthesis and release of glutamine and alanine at the cellular level can occur at a number of points. The accelerated proteolytic state found in the muscle-wasting diseases appears to be caused, at least in part, by insensitivity to the control mechanisms found in normal animals. The control of skeletal muscle glutamine metabolism appears to be the control of the balance between alanine and glutamine production and release allowing the most efficient response to the metabolically stressed state.
