The Effect of Long-term Treatment with Sulfonylurea Derivatives on Protein Metabolism in Diabetes Mellitus

In 101 diabetic adults without complications we determined before and during long-term treatment with sulfonylurea derivatives the serum protein content, electrophoretic serum composition, alkaline serum phosphatase, bromsulphalein retention, in serum, and in the twenty-four-hour urine free α-amino nitrogen and free α-amino acids were measured. The oxidative function of the liver was examined by loading with 2 gm. of methionine. The electrophoretic serum protein composition was only altered in sulfonylurea failure. After successful long-term treatment no changes in serum protein composition, alkaline serum phosphatase and bromsulphalein retention were found; however, the hyperaminoacidemia and hyperamino-aciduria decreased to normal values. The cause of this effect is probably an augmented production of insulin, which improves the oxidative deamination of amino acids in the liver.