Rat-urine glycosidases and kidney damage

Abstract

The activities of [beta]-galactosidase, [beta]-glucosidase, [beta]-glucuroni-dase and N-acetyl, [beta]-glucosaminidase were estimated in normal and pathological rat urine, with 4-methylumbelliferyl glycosides as substrates. Kidney damage induced by injections of uranium nitrate, mercuric chloride, potassium dichromate or 4-nitrophenylarsonic acid causes a marked increase in the urinary excretion of all four enzymes. The rise in [beta]-glucosidase activity was associated with the appearance of a new urinary enzyme species, which was examined by starch-gel electrophoresis, DEAE-cellulose chromatography and filtration on Sephadex G-75 and G-200. This enzyme appears to be identical with its counterpart in the kidney, and it is suggested that it arises in the urine as a result of renal tubular breakdown. The other glycosidases examined also show some physical similarities to the corresponding enzymes of the rat kidney.