Distal air space epithelial fluid clearance in near-term rat fetuses is fast and requires endogenous catecholamines

Hans G. Folkesson*, Michael A. Matthay, Cheryl J. Chapin, Nicolas F M Porta, Joseph A. Kitterman

*Corresponding author for this work

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

Knowledge about the conversion of the epithelium in the distal air spaces of the lung from secretion to absorption is imperative to the understanding of postnatal lung development; little such information is available in rats. Distal air space fluid clearance was therefore measured in 21- to 22-day gestation rat fetuses and newborn (40 h) rats. Distal air space fluid clearance was measured from the increase in 131I-albumin concentration in an isosmolar, physiological solution instilled into the developing lungs. There was no net fluid movement across the distal air space epithelium in the lungs of 21-day gestation fetuses. Twenty-four hours later, distal air space fluid was cleared at a rapid rate in the 22-day gestation fetuses. Within the first 40 h after birth, the rate rapidly declined to adult levels. The high distal air space fluid clearance at 22 days gestation and at 40 h after birth was mediated by β-adrenergic receptors as demonstrated by elevated plasma epinephrine levels and inhibition by propranolol. Interestingly, the elevated distal air space fluid clearance in the 22-day gestation fetuses was only minimally amiloride sensitive; however, amiloride sensitivity increased over the first 40 h after birth. In conclusion, these studies demonstrate that 1) rapid rates of net alveolar fluid clearance occur late in gestation in the rat and 2) this clearance is driven by elevations of endogenous epinephrine.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume282
Issue number3 26-3
StatePublished - Jun 29 2002

Keywords

  • Amiloride sensitivity
  • Development
  • Distal air space epithelium; Epinephrine
  • Na transport
  • Neonatal respiratory distress syndrome
  • Pulmonary edema

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Cell Biology
  • Physiology

Fingerprint Dive into the research topics of 'Distal air space epithelial fluid clearance in near-term rat fetuses is fast and requires endogenous catecholamines'. Together they form a unique fingerprint.

  • Cite this