β-Galactosidase, β-glucosidase and N-acetyl- β-glucosaminidase in human kidney

The levels of N-acetyl- β-glucosaminidase, β-galactosidase and β-glucosidase activity in normal human kidney were determined fluorimetrically. All three glycosidases were studied by ion exchange chromatography and gel electrophoresis. N-acetyl- β-glucosamin idase exists in two forms, acidic and basic, closely resembling those in human spleen. There are also two forms of β-galactosidase, one of which appears to be identical with the single β-glucosidase component. The same enzymes were assayed in urine from normal subjects. In contrast to the kidney, the urinary level of β-galactosidase activity is greater than the N-acetyl- β-glucosaminidase, which occurs almost entirely in the acidic form. Only one form of β-galactosidase could be found and β-glucosidase could not be detected. The β-galactosidase and β-glucosidase activities in human kidney and urine have characteristics similar to the corresponding enzymes in the rat. The possible use of the glycosidases for the detection of kidney damage is discussed.