These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Regulation of alveolar epithelial cell phenotypes in fetal sheep: roles of cortisol and lung expansion.
    Author: Flecknoe SJ, Boland RE, Wallace MJ, Harding R, Hooper SB.
    Journal: Am J Physiol Lung Cell Mol Physiol; 2004 Dec; 287(6):L1207-14. PubMed ID: 15298856.
    Abstract:
    Our aim was to determine whether cortisol's effect on alveolar epithelial cell (AEC) phenotypes in the fetus is mediated via a sustained alteration in lung expansion. Chronically catheterized fetal sheep were exposed to 1) saline infusion, 2) cortisol infusion (122-131 days' gestation, 1.5-4.0 mg/day), 3) saline infusion plus reduced lung expansion, or 4) cortisol infusion plus reduced lung expansion. The proportions of type I and II AECs were determined by electron microscopy, and surfactant protein (SP)-A, -B, and -C mRNA levels were determined by Northern blot analysis. Cortisol infusions significantly increased type II AEC proportions (to 38.2 +/- 2.2%), compared with saline-infused fetuses (23.8 +/- 2.4%), and reduced type I AEC proportions (to 59.0 +/- 2.2%), compared with saline-infused fetuses (70.4 +/- 2.4%). Reduced lung expansion also increased type II AEC proportions (to 52.9 +/- 3.5%) and decreased type I AEC proportions (to 34.2 +/- 3.7%), compared with control, saline-infused fetuses. The infusion of cortisol into fetuses exposed to reduced lung expansion tended to further increase type II (to 60.3 +/- 2.1%, P = 0.066) and reduce type I AEC (to 26.6 +/- 2.3%, P = 0.07) proportions. SP-A, -B, and -C mRNA levels changed in parallel with the changes in type II AEC proportions. These results indicate that cortisol alters the proportion of type I and type II AECs via a mechanism unrelated to the degree of fetal lung expansion. However, reductions in fetal lung expansion appear to have a greater impact on the proportion of AECs than cortisol.
    [Abstract] [Full Text] [Related] [New Search]