Essential amino acid metabolism in maintenance dialysis patients

Oral and I.V. administration of a mixture of essential amino acids to normal and dialysis patients revealed: 1. First pass metabolism (FPM) occurred for all administered amino acids in both normal and dialysis patients, and was variable in both populations. however, FPM appeared lower for phenylalanine and higher for methionine in the dialysis group. 2. Net metabolic clearance rate was significantly lower (p less than 0.05) for leucine, isoleucine, threonine and phenylalanine, and tended to be lower for valine and lysine in the dialysis group. 3. With the exception of phenylalanine and valine the apparent volume of distribution did not differ between normals and maintenance dialysis patients. 4. These studies indicate the existence of a variety of significant abnormalities in the metabolism of specific essential amino acids, and suggests a defect in muscle metabolism of branched-chain amino acids in maintenance dialysis patients.