[Relation of enzyme distribution in the kidney and increase pattern of urinary N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transpeptidase (gamma-GTP) activities following CDDP administration].

Nephrotoxicity is the major side effect of CDDP and it develops renal tubular damage. In the present paper, we have studied acute effects of cis-dichlorodiamine platinum (CDDP, 20 mg daily for 5 days) on the renal tubule using urinary NAG and gamma-glutamyltranspeptidase (gamma-GTP) activities as indicators of the toxicity. Altogether 25 courses of chemotherapy in 15 patients who had malignant tumors were studied. Urinary enzyme activities consisting of N-acetyl-beta-D-glucosaminidase (NAG, lysosomal enzyme) and gamma-GTP (brush border enzyme) were measured for 11 days from the day before CDDP administration. In all cases, both urinary enzyme activities increased with CDDP administration. The increase of NAG activity was transient; the highest level was detected on the 5th day of chemotherapy and decreased after that. On the other hand, two peaks of gamma-GTP activity were observed in many cases, the first peak during chemotherapy and the second peak soon after the completion of CDDP administration. The differences in increase pattern of these two urinary enzyme activities, suggest that changes of brush border occur in an early stage and cellular tissue including lysosome of renal tubule is impaired afterwards.