Intra-amniotic LPS amplifies hyperoxia-induced airway hyperreactivity in neonatal rats.

Published

Journal Article

BACKGROUND:We previously showed that intra-amniotic lipopolysaccharide (LPS) amplifies alveolar hypoplasia induced by postnatal hyperoxia. We determined whether the priming effect of intra-amniotic LPS amplifies hyperoxia-induced airway hyperreactivity (AHR). METHODS:LPS or normal saline was injected into the amniotic cavities of pregnant rats at the 20th day of gestation. After birth, rat pups were exposed to 60% O₂ or air for 14 d. On postnatal day 14, rat pups underwent forced oscillometry, which included a challenge with nebulized methacholine, and the lungs were harvested for morphological studies. RESULTS:Hyperoxia significantly increased airway reactivity and decreased compliance. Intra-amniotic LPS further increased hyperoxia-induced AHR but did not further impair respiratory system compliance. Hyperoxia-induced changes in lung parenchymal and small airway morphology were not further altered by intra-amniotic LPS. However, combined exposure to intra-amniotic LPS and hyperoxia increased the proportion of degranulating mast cells in the hilar airways. CONCLUSION:Intra-amniotic LPS amplified postnatal hyperoxia-induced AHR. This was associated with increased airway mast cell degranulation, which has previously been linked with hyperoxia-induced AHR. There were no morphologic changes of parenchyma or airways that would account for the LPS augmentation of hyperoxia-induced AHR.

Full Text

Cited Authors

  • Choi, CW; Kim, BI; Mason, SN; Potts-Kant, EN; Brahmajothi, MV; Auten, RL

Published Date

  • July 2013

Published In

Volume / Issue

  • 74 / 1

Start / End Page

  • 11 - 18

PubMed ID

  • 23563192

Pubmed Central ID

  • 23563192

Electronic International Standard Serial Number (EISSN)

  • 1530-0447

International Standard Serial Number (ISSN)

  • 0031-3998

Digital Object Identifier (DOI)

  • 10.1038/pr.2013.58

Language

  • eng