Acidosis and glucocorticoids induce branched-chain amino acid catabolism.

Chronic renal failure (CRF) is frequently complicated by malnutrition and wasting. The loss of lean body mass in CRF is the result of accelerated protein and amino acid degradation. Both appear to occur via acidosis-induced, glucocorticoid-dependent processes. In skeletal muscle, acidosis stimulates the activity of the rate-limiting enzyme in branched-chain amino acid metabolism, branched-brain ketoacid dehydrogenase (BCKAD). The activation of BCKAD in acidosis is likely to be glucocorticoid-dependent.