Enzymes in urine as markers of nephrotoxicity of cytostatic agents and aminoglycoside antibiotics.

A serious undesired action of the large group of cytostatics and aminoglycoside antibiotics is their side effect on the kidney. The aim of the study was to look for sensitive indicators that facilitate a quick evaluation of the nephrotoxicity of these drugs. For this purpose, the following substances were determined in urine: N-acetyl-beta-B-D-glucosaminidase (NAG) as well as its isoenzyme NAG-B, alanylaminopeptidase (AAP), gamma glutamyltransferase (GGT) and beta2-microglobulin (beta2M). The studies were carried out in two groups of patients treated with aminoglycoside antibiotics or cisplatin at different time intervals. The results obtained indicate that determination of NAG activity in urine may be used as a screening test that facilitates early detection of the nephrotoxic effects of the drugs tested. Separation of the NAG isoenzymes by column ion-exchange chromatography on the DEAE-52 cellulose as well as by electrophoresis in 7% polyacrylamide gel confirms the diagnostic value of this enzyme due to the ability of indicating the site of renal damage.