title: Urinary angiotensinogen level is increased in preterm neonates.
abstract: BACKGROUND
  All components of the renin-angiotensin system (RAS) are abundantly synthesized in the developing kidney, suggesting that the RAS plays an important role in renal development. To examine this system in human neonates, we measured urinary angiotensinogen levels in preterm and full-term neonates and examined the relationship between urinary angiotensinogen levels and gestational age.
  
  
  METHODS
  Urine and plasma samples were collected from 20 preterm and 18 full-term neonates at birth. Angiotensinogen levels were measured using enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Plasma angiotensinogen concentrations were not increased in preterm neonates compared with that in full-term neonates (P = 0.7288). However, the urinary angiotensinogen-to-creatinine ratio was significantly higher in preterm neonates compared with that in full-term neonates (P = 0.0011). Importantly, the urinary angiotensinogen-to-creatinine ratio dropped significantly with increasing gestational age (P = 0.0010), whereas the plasma angiotensinogen concentration was not correlated with gestational age (P = 0.7814).
  
  
  CONCLUSIONS
  These results suggest that urinary angiotensinogen levels may indicate the involvement of intrarenal RAS activation in prenatal renal development.
authors.affiliation: Department of Pediatrics, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho 3-18-15, Tokushima, Tokushima, 770-8503, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Suzue
authors.forename: Maki
authors.initials: M
authors.lastname: Urushihara
authors.forename: Ryuji
authors.initials: R
authors.lastname: Nakagawa
authors.forename: Takahiko
authors.initials: T
authors.lastname: Saijo
authors.forename: Shoji
authors.initials: S
authors.lastname: Kagami
mesh_terms: D000808:Angiotensinogen / Q000097:blood / Q000652:urine*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016022:Case-Control Studies; D003404:Creatinine / Q000652:urine*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D047928:Premature Birth / Q000097:blood / Q000652:urine*; D012084:Renin-Angiotensin System / Q000502:physiology*; D047929:Term Birth
chemical_list: D015415:Biomarkers; D000808:Angiotensinogen; D003404:Creatinine