MUSCLE PROTEIN-TURNOVER IN CHRONIC-RENAL-FAILURE PATIENTS WITH METABOLIC-ACIDOSIS OR NORMAL ACID-BASE-BALANCE

It is currently unknown if metabolic acidosis has any effect on muscle protein metabolism in patients with chronic renal failure (CRF), To a ddress this question, muscle protein turnover was studied in patients with CRF and controls in the postabsorptive state by using the forearm perfusion method together with the H-3-phenylalanine kinetics. Nine p atients were acidotic ([HCO3-](a) = 20 +/- 0.5 mEq/l) whereas 4 patien ts had a normal acid-base balance ([HCO3-](a) = 25+/-0.3 mEq/l). ln pa tients with metabolic acidosis the rates of phenylalanine appearance a nd disposal from the forearm were increased as compared to controls. P henylalanine net balance, i.e. net proteolysis, was only slightly high er than in controls. In patients under a normal acid-base balance both rates of appearance and disposal of phenylalanine as well as phenylal anine net balance were similar to controls. These preliminary data sug gest that metabolic acidosis can enhance the rate of muscle protein de gradation in patients with CRF.