title: [N-acetyl-beta-hexosaminidase--marker of damage to renal proximal tubules].
abstract: Cells of the renal epithelium synthesize and excrete to urine many enzymes. Among more than 50 enzymes produced by epithelial cells of proximal tubules, only few have a diagnostic value. Determination of the enzymatic activities in urine is sensitive and not invasive method for evaluation the function of renal tubules. Urinary N-acetyl-beta-hexosaminidase (HEX) activity is approved and practically utilized marker of the renal function. HEX is a lysosomal exoglycosidase taking part in catabolism of the sugar chains of glycoconjugates (glycoproteins, glycolipids and proteoglycans). HEX catalyses release of N-acetylglucosamine and N-acetylgalactosamine from a non reducing ends of glycoconjugates. In urine of healthy persons activity of HEX is negligible, but significantly increases after damage to the proximal tubules. The cells of renal proximal tubules are very sensitive to hypoxia. Therefore all renal processes with hypoxia lead to dysfunction of proximal renal tubules and release HEX to urine. Increased activity of HEX in urine was found after intoxication by heavy metals, nephrotoxic drugs, contrast media, fewer, bacterial as well as immunological nephritis and hypertension, diabetes, neoplasms and during renal graft rejection. In the paper we presented review of literature concerning HEX, and its presence in renal tissue and urine, as well as application in diagnostics.
authors.affiliation: Instytut Pomnik-Centrum Zdrowia Dziecka w Warszawie, Zakład Diagnostyki Laboratoryjnej.
authors.forename: Alina
authors.initials: A
authors.lastname: Kepka
authors.forename: Sławomir D
authors.initials: SD
authors.lastname: Szajda
authors.forename: Anna
authors.initials: A
authors.lastname: Jankowska
authors.forename: Napoleon
authors.initials: N
authors.lastname: Waszkiewicz
authors.forename: Sylwia
authors.initials: S
authors.lastname: Chojnowska
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Zwierz
mesh_terms: D015415:Biomarkers / Q000652:urine; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis* / Q000652:urine*; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism / Q000652:urine*
chemical_list: D015415:Biomarkers; D001619:beta-N-Acetylhexosaminidases