title: Urinary glycosaminoglycan composition in chronic glomerulonephritis.
abstract: BACKGROUND
  Glycosaminoglycans (GAG) play an important role in regulating glomerular permeability, and a reduction in their plasmatic concentration or urinary loss has been implicated in the pathogenesis of diseases associated with increased albumin permeability. The purpose of this study was to evaluate GAG excretion in renal pathology by analyzing the composition of urinary GAG in antibody mediated glomerular injury, such as mesangial glomerulonephritis (IgAGN) and primitive membranous glomerulonephritis (MGN), to verify the effects of glomerular capillary wall lesion with and without mesangial cell injury.
  
  
  METHODS
  Urinary GAG excretion was analyzed in 20 patients with IgAGN, 18 patients with MGN, and in 18 healthy subjects (controls). GAG were isolated from 24-hr urine using ion-exchange chromatography on DEAE-Sephacel, and the results are expressed as mg hexuronate/g creatinine (Cr). GAG composition was determined by cellulose acetate electrophoresis and expressed as relative percentages by densitometric scanning of Alcian Blue stained strips.
  
  
  RESULTS
  We found total GAG levels significantly higher in the urine of patients with MGN in comparison with controls and patients with IgAGN. The electrophoretic pattern analysis demonstrated low sulfated chondroitin sulfate proteoglycan (LSC-PG) in all patients compared to 44% in controls (8/18), but also low sulfated chondroitin sulfate (LSC) in 18.4% of patients (7/38) and slow migrating LSC (SM-LSC) in 8% of patients (3/38), only in the MGN group. Moreover, in patients with MGN, the LSC-PG relative content was significantly higher when compared to that observed in controls. Finally, in IgAGN and MGN patients, a significant reduction in chondroitin sulfate (CS) relative content was observed.
  
  
  CONCLUSIONS
  It seems likely that an increase in total GAG levels takes place when a reduction in renal function occurs, but the alteration of CS and herapan sulfate (HS) relative contents, and the presence of LSC-PG and free LSC also in the urine of IgAGN patients, allows us to suggest that the GAG distribution pattern becomes abnormal before an increase in total urine GAG excretion. In addition, the quali-quantitative determination of urinary GAG and GAGprotein complex could constitute an additional non-invasive marker to appraise the metabolism of renal connective tissue in some renal diseases.
authors.affiliation: Department of Physiological, Biochemical and Cellular Science, University of Sassari, Italy. demuro@uniss.it
authors.forename: Pierina
authors.initials: P
authors.lastname: De Muro
authors.forename: Rossana
authors.initials: R
authors.lastname: Faedda
authors.forename: Andrea
authors.initials: A
authors.lastname: Satta
authors.forename: Donatella
authors.initials: D
authors.lastname: Finetti
authors.forename: Antonio
authors.initials: A
authors.lastname: Masala
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cigni
authors.forename: Giovanni Maria
authors.initials: GM
authors.lastname: Sanna
authors.forename: Gian Mario
authors.initials: GM
authors.lastname: Cherchi
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria; D016022:Case-Control Studies; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D005920:Glomerular Mesangium / Q000473:pathology; D015432:Glomerulonephritis, Membranoproliferative / Q000097:blood / Q000473:pathology / Q000652:urine*; D015433:Glomerulonephritis, Membranous / Q000097:blood / Q000473:pathology / Q000652:urine*; D006025:Glycosaminoglycans / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011509:Proteoglycans / Q000652:urine
chemical_list: D006025:Glycosaminoglycans; D011509:Proteoglycans; D003404:Creatinine