title: Low oxygen exposure does not cause pulmonary injury in the newborn rat.
abstract: BACKGROUND
  Two recent studies have suggested that low levels of supplemental inspired oxygen may cause lung injury in preterm infants.
  
  
  OBJECTIVE
  To assess lung injury of newborn rats exposed to 14 days of low-level variation of oxygen.
  
  
  METHODS
  Four groups were compared with 12 animals per group and 4 lung sections per animal. These were, a control group raised in room air and three groups raised in levels of inspired oxygen fluctuating around the following mean values: group Lo (mean FiO(2) 0.179), group N (mean FiO(2) 0.213), and group Hi (mean FiO(2) 0.247). The degree of oxygen variability was identical for each group. Lungs were inflated at 20 cm H(2)O, fixed and stained with H and E and Millers Elastin.
  
  
  METHODS
  Sprague Dawley albino newborn rats.
  
  
  METHODS
  Random alveolar areas were studied and analysed using imaging software to assess total amount of tissue and elastin, number of secondary septa, and mean linear intercept.
  
  
  RESULTS
  There were no significant differences between the three experimental oxygen groups and the control group in terms of lung/body weight ratio and the measured markers of lung development.
  
  
  CONCLUSIONS
  We conclude that low-level oxygen supplementation during early lung development does not affect alveolar development in the newborn rat.
authors.affiliation: Child Life and Health, Edinburgh, UK. anncwhite@yahoo.co.uk
authors.forename: A
authors.initials: A
authors.lastname: White
authors.forename: J R
authors.initials: JR
authors.lastname: McColm
authors.forename: J
authors.initials: J
authors.lastname: Wade
authors.forename: Z
authors.initials: Z
authors.lastname: Yaqoob
authors.forename: K
authors.initials: K
authors.lastname: Sedowofia
authors.forename: B
authors.initials: B
authors.lastname: Fleck
authors.forename: N
authors.initials: N
authors.lastname: McIntosh
authors.forename: A
authors.initials: A
authors.lastname: Hislop
authors.forename: S
authors.initials: S
authors.lastname: Cunningham
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005260:Female; D008168:Lung / Q000473:pathology; D055370:Lung Injury; D010100:Oxygen / Q000008:administration & dosage*; D011247:Pregnancy; D011650:Pulmonary Alveoli / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010100:Oxygen