Studies on the Metabolism of Plasma Proteins in the Nephrotic Syndrome

It is now generally agreed that the proteinuria in the nephrotic syndrome cannot be attributed to the excretion of abnormal plasma proteins but is related directly to the lesion in the kidney. The present study was undertaken to determine whether the hypoproteinemia was due entirely to the proteinuria or if other factors such as defective synthesis or increased catabolism of the serum proteins play a role in development of hypoproteinemia in this syndrome. The rate of disappearance of radio-iodinated plasma proteins which were injected into patients with the nephrotic syndrome was studied. It was concluded that the rates of synthesis of albumin, gamma globulin, and iron-binding globulin were normal in this syndrome. The deficiencies of these substances in the plasma of children with the nephrotic syndrome appear to be due to an increased fractional rate of catabolism of these proteins in association with renal losses.