A Study of the Mechanism of Proteinuria in Patients with the Nephrotic Syndrome 1

Abstract
Values for the minimum concn. of albumin in the glomerular fluid of patients with the nephrotic syndrome were calculated from the rate of excretion of albumin and the endogenous creati-nine-likechromogen clearance. The concns., adjusted to the values which, other factors remaining constant, would obtain at the normal plasma albumin concn. of 4.0 g. per 100 ml., are considerably greater than the 25 to 30 mg. per 100 ml. assumed to be normally present. It is concluded that proteinuria in these patients occurs as the result of an increase in the permeability of the glomerular capillary walls to protein rather than solely as the result of a decrease in the reabsorption of protein by the tubules.