Urinary enzyme excretion as a indicator of nephrotoxicity in dependence on age

It was tested whether or not the measurement of urinary enzyme excretion is suitable for detection of nephrotoxic effects in newborn and in old aged rats in the same way as in adult rats. In rats of different ages the renal excretion of lactate dehydrogenase (LDH), leucine aminopeptidase (LAP) and alkaline phosphatase (alP) was measured after administration of a single nephrotoxic dose of uranyl nitrate (0.6 mg/100 g b.wt.). In adult and old aged rats the three enzymes indicate the nephrotoxic effect reliably. In 15- and 20-day-old rats only the alkaline phosphatase seems to be an indicator for the nephrotoxicity of uranyl nitrate. There are differences in the time course of enzymuria in dependence on age.