title: Plasma angiotensin II concentrations in the early neonatal period.
abstract: BACKGROUND
  There have been only a few reports on the renin-angiotensin system in low birthweight infants; in particular, plasma angiotensin II concentrations have not been studied.
  
  
  OBJECTIVE
  To investigate plasma angiotensin II concentrations in early neonatal infants including low birthweight infants.
  
  
  METHODS
  Forty six patients were studied, of whom 14 weighed not less than 2500 g (normal birth weight), 16 weighed less than 2500 g but not less than 1500 g (moderately low birth weight), and 16 weighed less than 1500 g (very low birth weight). Blood samples were collected twice, on day 0 and day 7. Angiotensin II concentration was assayed using an enzyme immunoassay kit with a microplate.
  
  
  RESULTS
  Geometric means of angiotensin II concentrations on day 7 were 19 pg/ml in the normal birthweight group, 28 pg/ml in the moderately low birthweight group, and 76 pg/ml in the very low birthweight group. The concentrations on day 7 in the very low birthweight group were significantly higher than those in the normal birthweight and moderately low birthweight groups (p = 0.005, p = 0.031). There were significant correlations between angiotensin II concentration on day 7 and gestational age (r(s) = -0.4, p = 0.007) and birth weight (r(s) = -0.36, p = 0.016).
  
  
  CONCLUSIONS
  Specific physiological conditions associated with a very low birth weight are thought to be responsible for the increased concentration of angiotensin II on day 7. It is necessary to measure angiotensin II concentration for a longer period after birth and study the factors that could influence it.
authors.affiliation: Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 641-8509, Japan. miyawaki@wakayama-med.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Miyawaki
authors.forename: T
authors.initials: T
authors.lastname: Okutani
authors.forename: R
authors.initials: R
authors.lastname: Higuchi
authors.forename: N
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D000375:Aging / Q000097:blood; D000804:Angiotensin II / Q000097:blood*; D001724:Birth Weight; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight / Q000097:blood; D007231:Infant, Newborn / Q000097:blood*; D019102:Infant, Very Low Birth Weight / Q000097:blood
chemical_list: D000804:Angiotensin II