Urinary proteins in occupational exposure to chemicals and in diseases

Isoelectric focusing in thin-layer polyacrylamide gel is a method with high resolving power, e.g. for urinary proteins. Therefore more information can be obtained with this method than with ordinary electrophoresis. The present version of the method has a high capacity and allows study of up to 25 samples in parallel on each gel. Only a little more than one hour is required for separation. A sensitive staining procedure is used which allows detection of as little as 0.1 mug of protein in each zone. When effects on the kidney are present more than 20 different protein zones can sometimes be separated. Evaluation is made by densitometry as well as by comparison and classification of patterns. Urine samples have been studied from workers with varying exposure to cadmium lead and various chlorinated hydrocarbons, and patients with glomerulonephritis, pyelonephritis, nephrosis and mixed tubular and glomerular diseases. Typical tubular patterns, i.e. as developed in association with cadmium exposure were characterized by elevated excretion of beta1-microglobulin. Other types of kidney malfunction showed different features.