N-Acetyl-beta-
glucosaminidase,
beta-galactosidase,
beta-glucosidase, acid and
alkaline phosphatase were monitored in urine kidney homogenates and serum of rats with papillary damage induced with
ethyleneimine. Serum
urea levels, total
protein in the urine and urine volume were monitored throughout the study. Histological studies showed that the injection of
ethyleneimine caused immediate papillary
necrosis, followed later by secondary cortical involvement. Minor papillary
necrosis induced by a low dose (0.5 mul/kg) of
ethyleneimine was characterised by a rise in urinary N-acetyl-beta-
glucosaminidase activity which was followed later by an increase in the activity of the other
enzymes monitored. More severe papillary
necrosis induced with a higher dose of
ethyleneimine (5.0 mul/kg) resulted in an immediate rise in the activities of all the urinary
enzymes which then decreased only to rise again when cortical involvement occurred. Serum
urea was unaltered but urine volume and
protein were increased coincidentally with the urinary
enzyme activities. The value of the assay of urinary
enzymes in distinguishing papillary from glomerular and tubular damage is assessed. The possible relevance of the
ethyleneimine model to the etiology of papillary nephropathy is discussed.