[Enzymes in urine following administration of hypertonic solutions]

3 patients with chronic nephropathies were given 20 ml of a diatrizoate-X-ray contrast medium, 500 ml of a 10% mannitol solution and 500 ml of a 10% dextran solution intravenously, and the behaviour of the excretion of protein, alanine aminopeptidase, beta-glucuronidase, aryl sulphatase A and lysozyme with the urine was tested. After application of these substances a transient increase of the excretion of alanine aminopeptidase, aryl sulphatase A and protein takes place. Conspicuous is the temporary decrease of the beta-glucuronidase activity in the urine after application of these hypertonic solutions. As a common cause of these changes alterations of the tubular cell in the sense of an osmotic nephropathy are to be assumed.