title: [Expression of heme oxygenase-1 and inducible nitric oxide synthase in the lungs of hyperoxia-exposed preterm rats].
abstract: OBJECTIVE
  To study the expression and the role of heme oxygenase-1 (HO-1) and inducible nitric oxide synthase (iNOS) in preterm rats with hyperoxia-induced lung injuries.
  
  
  METHODS
  Sixty-four three-day-old preterm Sprague-Dawley rats were randomly assigned to a hyperoxia group (90% oxygen exposure) and a control group (room air exposure), with 32 rats in each group. After 3 days or 7 days of exposure, the lung activity of HO-1 and nitric oxide (NO) contents in bronchoalveolar lavage fluid (BALF), pulmonary histopathologic changes, and the cellular distribution and expression of HO-1 and iNOS in the lungs were measured.
  
  
  RESULTS
  After 3 days and 7 days of exposure, the hyperoxia group showed acute lung injuries characterized by the presence of hyperaemia, red cell extravasation and inflammatory infiltration. The NO contents in BALF and the iNOS expression in the lungs increased significantly in the hyperoxia group compared with those in the control group 3 and 7 days after exposure. The expression of HO-1 in macrophages in the lungs increased significantly in the hyperoxia group compared with that in the control group 3 and 7 days after exposure. The NO contents in BALF and the iNOS and HO-1 expression in the lungs increased significantly 7 days after hyperoxia exposure compared with 3 days after hyperoxia exposure.
  
  
  CONCLUSIONS
  iNOS and HO-1 levels in the lungs increase in preterm rats with hyperoxia-induced lung injuries, suggesting that iNOS and HO-1 may play roles in hyperoxia-induced pulmonary injuries.
authors.affiliation: Department of Neonatology, Affiliated Hospital of Guilin Medical College, Guilin, Guangxi 541001, China.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Quan
authors.forename: Ming-Ci
authors.initials: MC
authors.lastname: Zheng
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Pei-Lin
authors.initials: PL
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005260:Female; D006419:Heme Oxygenase (Decyclizing) / Q000032:analysis* / Q000502:physiology; D018496:Hyperoxia / Q000150:complications / Q000201:enzymology*; D008168:Lung / Q000201:enzymology*; D055370:Lung Injury / Q000209:etiology*; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000032:analysis* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat