Effect of sodium tetrathionate on the activities of some enzymes in kidney and urine.

The activities of lactate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase, beta-galactosidase, N-acetyl-beta-D-glucosaminidase, leucine aminopeptidase, gamma-glutamyltransferase and alkaline phosphatase in renal tissue and urine of rats treated with sodium tetrathionate were determined. A decrease of enzyme activities in renal tissue and an increase in urine were observed. The largest decrease in the glutamate dehydrogenase of renal tissue amounted to 0.7 times the control value, and was correlated with an appropriate increase in the urine. Increases in urinary enzyme activity were especially marked for beta-galactosidase and N-acetyl-beta-D-glucosaminidase (3 and 6 times the control values, respectively). The increase in enzyme activities was not accompanied by a corresponding change in the urinary protein. Characterization of urinary lactate dehydrogenase and N-acetyl-beta-D-glucosaminidase isoenzymes also indicates the renal origin of these enzymes. The abnormally high enzyme activities of the urine correlated with the nature and degree of renal damage shown by electron microscopy.