Alanine and aspartate aminotransferases in normal and denervated skeletal muscle.

Activities of alanine and aspartate aminotransferases are maintained during the first 5 weeks of growth, but decrease subsequently in normal chick gastrocnemii. In sciatectomized muscles, a 5-fold elevation in these enzymes reveals increased utilization of amino acids as a compensatory metabolic support during denervation atrophy.