title: [Expression of ERK1/2 protein in lung tissues of newborn rats with hyperoxia-induced chronic lung disease].
abstract: OBJECTIVE
  To study the expression of extracellular signal regulated protein kinase (ERK) 1/2 in lung tissues of newborn rats with chronic lung disease (CLD) caused by hyperoxia.
  
  
  METHODS
  Forty-eight full-term newborn rats were randomly divided into two groups: hyperoxia and control. The two groups were exposed to a hyperoxic gas mixture (0.90 O(2)) for an induction of CLD and room air within 12 hrs after birth, respectively. The levels of ERK1/2 protein and mRNA in lung tissues were measured using immunohistochemistry, Western blot and real-time PCR methods on postnatal days 3, 7 and 14. The severity of pulmonary fibrosis was evaluated.
  
  
  RESULTS
  The expression of p-ERK protein in lung tissues in the hyperoxia group was significantly higher than that in the control group on postnatal days 7 and 14 (P<0.01). There were no significant differences in the levels of total ERK1/2 protein and ERK1/2 mRNA.
  
  
  CONCLUSIONS
  The activation of phosphorated ERK1/2 may lead to lung fibrosis caused by hyperoxia in newborn rats.
authors.affiliation: Department of Pediatrics, Shengjing Hospital, China Medical University, Shenyang 110004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hu
authors.forename: Xue-Yan
authors.initials: XY
authors.lastname: Liu
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Fu
authors.forename: Xin-Dong
authors.initials: XD
authors.lastname: Xue
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002908:Chronic Disease; D005260:Female; D018496:Hyperoxia / Q000150:complications*; D008168:Lung / Q000201:enzymology* / Q000473:pathology; D008171:Lung Diseases / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000032:analysis*; D048052:Mitogen-Activated Protein Kinase 3 / Q000032:analysis*; D010766:Phosphorylation; D011658:Pulmonary Fibrosis / Q000209:etiology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3