Histochemical analyses of altered fetal lung development following single vs multiple courses of antenatal steroids.

Published

Journal Article

A single course of antenatal steroids is widely used during preterm labor to promote fetal lung maturation. However, little is known regarding efficacy and safety of multiple courses of antenatal steroids. In animal models and clinical trials, treatment with glucocorticoids can inhibit growth. The present study of single- vs multiple-course steroids in pregnant ewes analyzes the effects of steroids vs placebo on fetal lung histopathology. Single-course groups received dexamethasone (Dex) 6 mg or normal saline every 12 hr for 48 hr at 104-106 days of gestation (term = 150 days). Multiple-course groups received the first course at 76-78 days; this was repeated weekly for 5 weeks. At 108 days, lungs were analyzed using immunohistochemistry for alpha-smooth muscle actin, a myofibroblast marker and proliferating cell nuclear antigen. Cell injury/death was evaluated using TdT-mediated dUTP digoxigenin nick end labeling (TUNEL) analysis. Although fetal growth was restricted by either single or multiple courses of Dex, alveolar development was accelerated as measured by mean linear intercepts. Alveolar walls were thinner, developing septa were longer, and septal myofibroblasts were increased for both Dex groups compared with controls. Cell proliferation increased following multiple steroid courses, especially in the distal parenchyma, with a corresponding decrease in apoptosis. These observations suggest that Dex promotes alveolarization, whether given in single or multiple courses.

Full Text

Duke Authors

Cited Authors

  • Pua, ZJ; Stonestreet, BS; Cullen, A; Shahsafaei, A; Sadowska, GB; Sunday, ME

Published Date

  • December 2005

Published In

Volume / Issue

  • 53 / 12

Start / End Page

  • 1469 - 1479

PubMed ID

  • 15956023

Pubmed Central ID

  • 15956023

International Standard Serial Number (ISSN)

  • 0022-1554

Digital Object Identifier (DOI)

  • 10.1369/jhc.5A6721.2005

Language

  • eng

Conference Location

  • United States