| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Children's Hospital Oakland Research Institute, Oakland 94609; School of Optometry and Department of Molecular and Cell Biology, University of California, Berkeley 94720; and Cardiovascular Research Institute, University of California, San Francisco, California 94143
Elevated levels of Na and Cl in airway surface liquid may play a major role in the airway pathology of cystic fibrosis (CF) (J. J. Smith, S. M. Travis, E. P. Greenberg, and M. J. Welsh. Cell 85: 229-236, 1996) and could be caused by block of transcellular Cl absorption due to lack of a functional CF transmembrane conductance regulator (CFTR). To test for transcellular absorption of Cl across non-CF epithelium, we studied how fluid absorption was affected by the opening and closing of Cl channels. Forskolin (an activator of CFTR) tripled fluid absorption across primary cultures of bovine tracheal epithelium but had no effect on human cells. However, in both species, fluid absorption was markedly inhibited by 5-nitro-2-(3-phenylpropylamino)benzoate, a blocker of CFTR. Microelectrode studies suggested that the magnitude of the absorptive response to forskolin in bovine cells depended on the size of an inwardly directed electrochemical driving force for Cl movement across the apical membrane. Patch-clamp measurements of bovine cells revealed CFTR in the apical membrane and a cAMP-activated, inwardly rectifying Cl channel in the basolateral membrane. We conclude that a significant fraction of absorbed Cl passes transcellularly in bovine tracheal epithelial cultures, with CFTR as the path of entry in the apical membrane and a novel cAMP-activated Cl channel as the exit route in the basolateral membrane. Our data further indicate that a similar pathway may exist in non-CF human tracheal epithelium.
adenosine 3',5'-cyclic monophosphate; cystic fibrosis; airway surface liquid; epithelial ion transport
This article has been cited by other articles:
|
|
 |
|
  O. A. Itani, F. S. Lamb, J. E. Melvin, and M. J. Welsh Basolateral chloride current in human airway epithelia Am J Physiol Lung Cell Mol Physiol, October 1, 2007; 293(4): L991 - L999. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. E. Machen Innate immune response in CF airway epithelia: hyperinflammatory? Am J Physiol Cell Physiol, August 1, 2006; 291(2): C218 - C230. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Fang, Y. Song, R. Zemans, J. Hirsch, and M. A. Matthay Fluid transport across cultured rat alveolar epithelial cells: a novel in vitro system Am J Physiol Lung Cell Mol Physiol, July 1, 2004; 287(1): L104 - L110. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. F. Dubin, S. K. Robinson, and J. H. Widdicombe Secretion of lactoferrin and lysozyme by cultures of human airway epithelium Am J Physiol Lung Cell Mol Physiol, April 1, 2004; 286(4): L750 - L755. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Szkotak, S. F. P. Man, and M. Duszyk The Role of the Basolateral Outwardly Rectifying Chloride Channel in Human Airway Epithelial Anion Secretion Am. J. Respir. Cell Mol. Biol., December 1, 2003; 29(6): 710 - 720. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Lazrak and S. Matalon cAMP-induced changes of apical membrane potentials of confluent H441 monolayers Am J Physiol Lung Cell Mol Physiol, August 1, 2003; 285(2): L443 - L450. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. E. Phillips, J. A. Hey, and M. R. Corboz Effects of ion transport inhibitors on MCh-mediated secretion from porcine airway submucosal glands J Appl Physiol, September 1, 2002; 93(3): 873 - 881. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Crews, A. E. Taylor, and S. T. Ballard Liquid transport properties of porcine tracheal epithelium J Appl Physiol, August 1, 2001; 91(2): 797 - 802. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Blaug, K. Hybiske, J. Cohn, G. L. Firestone, T. E. Machen, and S. S. Miller ENaC- and CFTR-dependent ion and fluid transport in mammary epithelia Am J Physiol Cell Physiol, August 1, 2001; 281(2): C633 - C648. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. T. Chen and D. B. Yeates Ion transport and regulation of respiratory tract fluid output in dogs J Appl Physiol, March 1, 2001; 90(3): 821 - 831. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Widdcombe How does cAMP increase active Na absorption across alveolar epithelium? Am J Physiol Lung Cell Mol Physiol, February 1, 2000; 278(2): L231 - L232. [Full Text] [PDF]
|
|
|
|
|
|
S. M. O'Grady, X. Jiang, and D. H. Ingbar Cl-channel activation is necessary for stimulation of Na transport in adult alveolar epithelial cells Am J Physiol Lung Cell Mol Physiol, February 1, 2000; 278(2): L239 - L244. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. S. Pedersen, N.-H. Holstein-Rathlou, P. L. Larsen, K. Qvortrup, and O. Frederiksen Fluid absorption related to ion transport in human airway epithelial spheroids Am J Physiol Lung Cell Mol Physiol, December 1, 1999; 277(6): L1096 - L1103. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. H. Widdicombe Altered NaCl Concentration of Airway Surface Liquid in Cystic Fibrosis Physiology, June 1, 1999; 14(3): 126 - 127. [Full Text] [PDF]
|
|
|
|
|
|
X. C. Sun and J. A. Bonanno Expression, localization, and functional evaluation of CFTR in bovine corneal endothelial cells Am J Physiol Cell Physiol, April 1, 2002; 282(4): C673 - C683. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
