title: Antenatal betamethasone attenuates intrauterine infection-aggravated hyperoxia-induced lung injury in neonatal rats.
abstract: BACKGROUND
  Intrauterine infection can exacerbate postnatal hyperoxic lung injury. We hypothesized that antenatal betamethasone treatment attenuates hyperoxic lung injury aggravated by intrauterine infection in neonatal rats.
  
  
  METHODS
  Newborn Sprague-Dawley rats were divided into eight experimental groups according to (i) whether rats were exposed to normoxia (N) or hyperoxia (H, 85% oxygen) from postnatal day (P)1 to P14, (ii) whether antenatal betamethasone (0.2 mg/dose) or vehicle was administered to pregnant rats at gestation days (E)19 and E20, and (iii) whether intrauterine infection was induced or not antenatally. Intrauterine infection was induced by intracervical inoculation of Escherichia coli into pregnant rats on E19. We measured cytokine levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β in P1 rat lungs and performed morphometric analyses and assessed inflammatory responses in lung tissue and bronchoalveolar lavage (BAL) at P14 by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining and measurement of myeloperoxidase activity, collagen, and cytokine levels.
  
  
  RESULTS
  Cytokine levels in P1 rat lungs were increased by intrauterine infection, and these increases were attenuated by antenatal betamethasone. Hyperoxic lung injuries, indicated by morphometric changes and an inflammatory response in the lung and BAL fluid, were aggravated by intrauterine infection at P14. This aggravation was significantly attenuated by antenatal betamethasone.
  
  
  CONCLUSIONS
  Antenatal betamethasone attenuated aggravated hyperoxic lung injuries induced by intrauterine infection in neonatal rats via its anti-inflammatory actions.
authors.affiliation: Department of Pediatrics, Samsung Medical Center, School of Medicine Sungkyunkwan University, Seoul, South Korea.
authors.forename: Hye Soo
authors.initials: HS
authors.lastname: Yoo
authors.forename: Yun Sil
authors.initials: YS
authors.lastname: Chang
authors.forename: Jin Kyu
authors.initials: JK
authors.lastname: Kim
authors.forename: So Yoon
authors.initials: SY
authors.lastname: Ahn
authors.forename: Eun Sun
authors.initials: ES
authors.lastname: Kim
authors.forename: Dong Kyung
authors.initials: DK
authors.lastname: Sung
authors.forename: Ga Won
authors.initials: GW
authors.lastname: Jeon
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Hwang
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Shim
authors.forename: Won Soon
authors.initials: WS
authors.lastname: Park
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001623:Betamethasone / Q000008:administration & dosage*; D001992:Bronchoalveolar Lavage Fluid; D003094:Collagen / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004716:Endometritis / Q000150:complications*; D004927:Escherichia coli Infections / Q000150:complications*; D005260:Female; D018496:Hyperoxia / Q000150:complications*; D020287:In Situ Nick-End Labeling; D007958:Leukocyte Count; D008168:Lung / Q000201:enzymology / Q000378:metabolism; D055370:Lung Injury / Q000209:etiology / Q000517:prevention & control*; D009195:Peroxidase / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016207:Cytokines; D003094:Collagen; D001623:Betamethasone; D009195:Peroxidase