Alveolar epithelial ion and fluid transport - Ca2(+)-dependent stimulation of alveolar fluid clearance in near-term fetal guinea pigs
Title
Alveolar epithelial ion and fluid transport - Ca2(+)-dependent stimulation of alveolar fluid clearance in near-term fetal guinea pigs
Creator
Norlin A; Folkesson H G
Publisher
American Journal of Physiology-Lung Cellular and Molecular Physiology
Date
2002
2002-04
Description
We investigated the importance of changes in intracellular Ca2+ concentration ([Ca2+](i)) for amiloride-sensitive alveolar fluid clearance (AFC) in late-gestational guinea pigs. Fetal guinea pigs of 61, 68, and 69 days (term) gestation were investigated under normal conditions and after oxytocin-induced preterm labor. AFC or alveolar fluid secretion was measured using an impermeable tracer technique. At 61 days gestation there was net secretion of fluid into the lungs, and at birth the lungs cleared 49 +/- 7% of the instilled fluid volume over 1 h. Induction of preterm labor with oxytocin induced AFC at 61 days gestation. When present, AFC was inhibited or reversed to net fluid secretion by amiloride (10(-3) M). Inhibition of membrane Ca2+ channels by verapamil (10(-4) M) or depletion of intracellular Ca2+ by thapsigargin (10(-5) M) reduced AFC when net AFC was evident. Amiloride lacked an inhibitory effect on AFC when instilled with verapamil or thapsigargin. The results indicate that AFC via amiloride-sensitive pathways develops during late gestation, and that inducing preterm labor precociously may activate such pathways. Our results suggest that Ca2+ may act as a second messenger in mediating catecholamine-stimulated AFC.
Subject
adrenaline; agonist; amiloride; birth; blood-flow; cation; channel; distal lung epithelium; expression; lamb; liquid; oxytocin-induced preterm labor; Physiology; protein clearance; Respiratory System; sodium transport; surfactant secretion
Identifier
Format
Journal Article
URL Address
Search for Full-text
Users with a NEOMED Library login can search for full-text journal articles at the following url: https://libraryguides.neomed.edu/home
Rights
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
Pages
L642-L649
Issue
4
Volume
282
Citation
Norlin A; Folkesson H G, “Alveolar epithelial ion and fluid transport - Ca2(+)-dependent stimulation of alveolar fluid clearance in near-term fetal guinea pigs,” NEOMED Bibliography Database, accessed December 1, 2023, https://neomed.omeka.net/items/show/6653.