[Study on urinary beta-glucuronidase and alkaline phosphatase activities as indicators of CDDP renal toxicity]

Renal toxicity is the major side effect of cis-dichlorodiammine platinum (CDDP) and it develops renal tubular damage. In the present study, the acute changes of urinary beta-glucuronidase (beta-GL) and alkaline phosphatase (ALP) activities following CDDP administration as indicators of its toxicity were studied in 5 patients with urological malignant tumors. The activities were measured for 11 days continuously from the day before CDDP administration. In all cases, both urinary enzyme activities increased with CDDP administration. Increase patterns of urinary beta-GL activities were similar to those of urinary NAG, but remarkably-high values of beta-GL activities were found in cases of urothelial tumors probably because urinary beta-GL derives from the kidney (lysosomes of tubular cells) and from the epithelial cells of urinary tract. Urinary ALP activities changed corresponding well with urinary gamma-glutamyl transpeptidase (gamma-GTP). This study shows that the determination of urinary beta-GL is not a significant marker of CDDP renal toxicity, especially in cases with urological malignancies, in contrast to results for urinary brush border enzyme activities such as ALP or gamma-GTP.