Lysosomal enzymes are decreased in the kidney of diabetic rats

► Lysosomal enzyme activities are decreased in type 1 DM rat kidney. ► Decrease was observed for cathepsins and glycosidases. ► Aryl sulfatases did not vary. ► Proximal convoluted tubules had thinner walls and decreased brush border. ► Cathepsin B was located in the brush border of tubular cells.