AJP - Lung Cellular and Molecular Physiology, Vol 260, Issue 6 494-L500, Copyright © 1991 by American Physiological Society

ARTICLES

Developing fetal alveolar epithelial cells secrete fluid in primary culture

P. B. McCray Jr and M. J. Welsh
Pulmonary Department, Children's Hospital Oakland Research Institute, California 94609.

The developing pulmonary epithelium secretes a Cl(-)-rich fluid during fetal life by a process involving active transport. To determine if alveolar cells contribute to this fluid production, we studied developing fetal rat alveolar epithelial cells (18-day gestation) in primary culture. Fetal alveolar epithelial cells aggregated to form cystic, alveolar-like structures with a fluid-filled lumen. On light and transmission electron microscopy, the cells were polarized with microvilli facing the lumen. Dexamethasone and triiodothyronine stimulated lamellar body production in many of the epithelial cells of the cyst wall. The transepithelial voltage in the cyst was -2.4 +/- 0.4 mV (lumen negative), suggesting the presence of active electrolyte transport. Bumetanide, an inhibitor of Cl- secretion in other systems, decreased the size and number of cysts. A membrane-permeant analogue of adenosine 3',5'-cyclic monophosphate (cAMP) and 3-isobutyl-1-methylxanthine increased the size of cysts, an effect that was blocked by coincubation with bumetanide. The increased size of the cysts did not result from stimulation of cell growth; in fact, [3H]thymidine incorporation was inhibited to 40% control values by cAMP, suggesting that growth was inhibited rather than stimulated. These results suggest that fetal alveolar epithelial cells secrete fluid via a cAMP-mediated Cl(-)-secretory process. Secretion of fluid by the developing alveolar epithelium may play an important role in lung development.

This article has been cited by other articles:

				B. L. Daugherty, M. Mateescu, A. S. Patel, K. Wade, S. Kimura, L. W. Gonzales, S. Guttentag, P. L. Ballard, and M. Koval Developmental regulation of claudin localization by fetal alveolar epithelial cells Am J Physiol Lung Cell Mol Physiol, December 1, 2004; 287(6): L1266 - L1273. [Abstract] [Full Text] [PDF]

				S. M. O'Grady and S. Y. Lee Chloride and potassium channel function in alveolar epithelial cells Am J Physiol Lung Cell Mol Physiol, May 1, 2003; 284(5): L689 - L700. [Abstract] [Full Text] [PDF]

				D. J. Gillie, A. J. Pace, R. J. Coakley, B. H. Koller, and P. M. Barker Liquid and Ion Transport by Fetal Airway and Lung Epithelia of Mice Deficient in Sodium-Potassium-2-Chloride Transporter Am. J. Respir. Cell Mol. Biol., July 1, 2001; 25(1): 14 - 20. [Abstract] [Full Text] [PDF]

				J. S. Torday, H. Sun, and J. Qin Prostaglandin E2 integrates the effects of fluid distension and glucocorticoid on lung maturation Am J Physiol Lung Cell Mol Physiol, January 1, 1998; 274(1): L106 - L111. [Abstract] [Full Text] [PDF]