title: Urinary angiotensinogen accurately reflects intrarenal Renin-Angiotensin system activity.
abstract: BACKGROUND
  We recently reported that immunoreactivity of intrarenal angiotensinogen (AGT) is significantly increased in IgA nephropathy patients. Meanwhile, we have developed direct enzyme-linked immunosorbent assays to measure plasma and urinary AGT (UAGT) in humans. This study was performed to test the hypothesis that UAGT levels are increased in chronic glomerulonephritis patients.
  
  
  METHODS
  We analyzed 100 urine samples from 70 chronic glomerulonephritis patients (26 from IgA nephropathy, 24 from purpura nephritis, 8 from lupus nephritis, 7 from focal segmental glomerulosclerosis, and 5 from non-IgA mesangial proliferative glomerulonephritis) and 30 normal control subjects.
  
  
  RESULTS
  UAGT-creatinine ratio (UAGT/UCre) was correlated positively with diastolic blood pressure (p = 0.0326), urinary albumin-creatinine ratio (p < 0.0001), urinary protein-creatinine ratio (p < 0.0001) and urinary occult blood (p = 0.0094). UAGT/UCre was significantly increased in chronic glomerulonephritis patients not treated with renin-angiotensin system (RAS) blockers compared with control subjects (p < 0.0001). Importantly, glomerulonephritis patients treated with RAS blockers had a marked attenuation of this augmentation (p = 0.0021).
  
  
  CONCLUSIONS
  These data indicate that UAGT are increased in chronic glomerulonephritis patients and treatment with RAS blockers suppressed UAGT. The efficacy of RAS blockade to reduce the intrarenal RAS activity can be confirmed by measurement of UAGT in chronic glomerulonephritis patients.
authors.affiliation: Department of Physiology, and Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, USA.
authors.forename: Maki
authors.initials: M
authors.lastname: Urushihara
authors.forename: Shuji
authors.initials: S
authors.lastname: Kondo
authors.forename: Shoji
authors.initials: S
authors.lastname: Kagami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kobori
mesh_terms: D000293:Adolescent; D000328:Adult; D000808:Angiotensinogen / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005921:Glomerulonephritis / Q000503:physiopathology / Q000652:urine*; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D008297:Male; D012084:Renin-Angiotensin System / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D000808:Angiotensinogen