Faculty Collaboration Database

Water transport and the distribution of aquaporin-1 in pulmonary air spaces. J Appl Physiol (1985) 1997 Sep;83(3):1002-16

Date

09/18/1997

Pubmed ID

9292489

DOI

10.1152/jappl.1997.83.3.1002

Scopus ID

2-s2.0-0030770795 (requires institutional sign-in at Scopus site)   51 Citations

Abstract

Recent evidence suggests that water transport between the pulmonary vasculature and air spaces can be inhibited by HgCl2, an agent that inhibits water channels (aquaporin-1 and -5) of cell membranes. In the present study of isolated rat lungs, clearances of labeled (3HOH) and unlabeled water were compared after instillation of hypotonic or hypertonic solutions into the air spaces or injection of a hypotonic bolus into the pulmonary artery. The clearance of 3HOH between the air spaces and perfusate after intratracheal instillation and from the vasculature to the tissues after pulmonary arterial injections was invariably greater than that of unlabeled water, indicating that osmotically driven transport of water is limited by permeability of the tissue barriers rather than the rate of perfusion. Exposure to 0.5 mM HgCl2 in the perfusate and air-space solution reduced the product of the filtration coefficient and surface area (PfS) of water from the air spaces to the perfusate by 28% after instillation of water into the trachea. In contrast, perfusion of 0.5 mM HgCl2 in air-filled lungs reduced PfS of the endothelium by 86% after injections into the pulmonary artery, suggesting that much of the action of this inhibitor is on the endothelial surfaces. Confocal laser scanning microscopy demonstrated that aquaporin-1 is on mouse pulmonary endothelium. No aquaporin-1 was found on alveolar type I cells with immunogold transmission electron microscopy, but small amounts were present on some type II cells.

Author List

Effros RM, Darin C, Jacobs ER, Rogers RA, Krenz G, Schneeberger EE

MESH terms used to index this publication - Major topics in bold

Animals
Aquaporin 1
Aquaporins
Body Water
Cell Membrane Permeability
Female
Fluorescent Antibody Technique, Direct
Immunochemistry
Injections, Intra-Arterial
Ion Channels
Lung
Mercuric Chloride
Mice
Mice, Inbred BALB C
Microscopy, Confocal
Microscopy, Electron
Osmolar Concentration
Pulmonary Artery
Rabbits
Rats
Rats, Sprague-Dawley