title: Urinary enzymes and low-molecular-mass proteins as indicators of diabetic nephropathy.
abstract: We measured the excretion rates of six urinary enzymes that either originate from the proximal renal tubule, like alanine aminopeptidase (EC 3.4.11.2), alkaline phosphatase (EC 3.1.3.1), gamma-glutamyltransferase (EC 2.3.2.2), and N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30), or that are typical low-molecular-mass proteins, like lysozyme (EC 3.2.1.17) and pancreatic ribonuclease (EC 3.1.27.5). These rates were compared with those of total protein and albumin in urine of 36 insulin-dependent diabetic men and 30 healthy men. Seventeen of the diabetics had "clinical proteinuria," defined as excretion of more than 7.5 g of protein per mole of urinary creatinine (group B). Group A comprised the 19 diabetics without proteinuria. Except for gamma-glutamyltransferase, the excretions of enzymes and proteins were significantly higher in diabetics than in controls and were greater in group B than in group A. N-Acetyl-beta-D-glucosaminidase was the analyte most often increased in group A (89%), followed by albumin and alkaline phosphatase (each 32%). All patients in group B showed increased excretion of N-acetyl-beta-D-glucosaminidase. We conclude from the comparative data that this enzyme may be useful as an early predictor of diabetic nephropathy.
mesh_terms: D000118:Acetylglucosaminidase / Q000652:urine; D000328:Adult; D000419:Albuminuria / Q000201:enzymology; D000469:Alkaline Phosphatase / Q000652:urine; D000626:Aminopeptidases / Q000652:urine; D018826:CD13 Antigens; D003922:Diabetes Mellitus, Type 1 / Q000201:enzymology*; D003928:Diabetic Nephropathies / Q000201:enzymology*; D006801:Humans; D008297:Male; D009113:Muramidase / Q000652:urine; D011507:Proteinuria / Q000201:enzymology*; D012259:Ribonuclease, Pancreatic / Q000652:urine; D005723:gamma-Glutamyltransferase / Q000652:urine
chemical_list: D005723:gamma-Glutamyltransferase; D012259:Ribonuclease, Pancreatic; D000469:Alkaline Phosphatase; D009113:Muramidase; D000118:Acetylglucosaminidase; D000626:Aminopeptidases; D018826:CD13 Antigens