ABSTRACT
beta-Galactosidase, alpha-D-mannosidase, alpha-L-fucosidase and N-acetyl-beta-D-glucosaminidase activities were assayed in serum and urine from rats treated with three different doses of the nephrotoxic antibiotic tobramycin (100 mg/kg/day for 5 days, 10 mg/kg/day for 10 days and 5 mg/kg/day for 20 days) and gentamicin (100 mg/kg/day for 5 days). A significant increase of beta-galactosidase, N-acetyl-beta-D-glucosaminidase and alpha-L-fucosidase activities occurred in urine following the administration of high doses of antibiotic. The enzyme activity was dependent on the dose level used. The excretion of alpha-D-mannosidase was atypical and elevated activities were observed on some days but no pattern of excretion of this enzyme was established. No change in any of the four glycosidase activities was found in serum of treated rats. The results obtained when high doses of gentamicin were employed are similar to those obtained with a similar dose of tobramycin. These results indicate that the assay of urinary glycosidase activities provides a useful method for monitoring the nephrotoxicity of antibiotics.
