| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
2 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary and Critical Care Medicine, University of Southern California, Los Angeles, California 90033; and 1 School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
Using the patch-clamp technique, we studied the effects of
epidermal growth factor (EGF) on whole cell and single channel currents
in adult rat alveolar epithelial type II cells in primary culture in
the presence or absence of EGF for 48 h. In symmetrical sodium
isethionate solutions, EGF exposure caused a significant increase in
the type II cell whole cell conductance. Amiloride (10 µM) produced ~20-30% inhibition of the whole
cell conductance in both the presence and absence of EGF, such that EGF
caused the magnitude of the amiloride-sensitive component to more than double. Northern analysis showed that 
-, 
- and 
-subunits of rat epithelial Na+ channel (rENaC)
steady-state mRNA levels were all significantly decreased by EGF. At
the single channel level, all active inside-out patches demonstrated
only 25-pS channels that were amiloride sensitive and relatively
nonselective for cations
(PNa+/PK+ 
1.0:0.48). Although the biophysical characteristics (conductance, open-state probability, and selectivity) of the channels from EGF-treated and untreated cells were essentially identical, channel density was increased by EGF; the modal channel per patch was increased
from 1 to 2. These findings indicate that EGF increases expression of
nonselective, amiloride-sensitive cation channels in adult alveolar
epithelial type II cells. The contribution of rENaC to the total
EGF-dependent cation current under these conditions is quantitatively
less important than that of the nonselective cation channels in these cells.
sodium channels; alveolar epithelium; nonselective cation channels
This article has been cited by other articles:
|
|
 |
|
  G. M. Mutlu and J. I. Sznajder Mechanisms of pulmonary edema clearance Am J Physiol Lung Cell Mol Physiol, November 1, 2005; 289(5): L685 - L695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Mair, M. Frick, C. Bertocchi, T. Haller, A. Amberger, H. Weiss, R. Margreiter, W. Streif, and P. Dietl Inhibition by cytoplasmic nucleotides of a new cation channel in freshly isolated human and rat type II pneumocytes Am J Physiol Lung Cell Mol Physiol, December 1, 2004; 287(6): L1284 - L1292. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Dagenais, R. Frechette, Y. Yamagata, T. Yamagata, J.-F. Carmel, M.-E. Clermont, E. Brochiero, C. Masse, and Y. Berthiaume Downregulation of ENaC activity and expression by TNF-{alpha} in alveolar epithelial cells Am J Physiol Lung Cell Mol Physiol, February 1, 2004; 286(2): L301 - L311. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Bravo, C. U. Nielsen, J. Amstrup, S. Frokjaer, and B. Brodin Epidermal growth factor decreases PEPT2 transport capacity and expression in the rat kidney proximal tubule cell line SKPT0193 cl.2 Am J Physiol Renal Physiol, February 1, 2004; 286(2): F385 - F393. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. C. Willis, K.-J. Kim, X. Li, J. Liebler, E. D. Crandall, and Z. Borok Modulation of ion conductance and active transport by TGF-{beta}1 in alveolar epithelial cell monolayers Am J Physiol Lung Cell Mol Physiol, December 1, 2003; 285(6): L1192 - L1200. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.-P. Shen and C. U. Cotton Epidermal growth factor inhibits amiloride-sensitive sodium absorption in renal collecting duct cells Am J Physiol Renal Physiol, January 1, 2003; 284(1): F57 - F64. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Matthay, C. Clerici, and G. Saumon Lung Edema Clearance: 20 Years of Progress: Invited Review: Active fluid clearance from the distal air spaces of the lung J Appl Physiol, October 1, 2002; 93(4): 1533 - 1541. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Matthay, H. G. Folkesson, and C. Clerici Lung Epithelial Fluid Transport and the Resolution of Pulmonary Edema Physiol Rev, July 1, 2002; 82(3): 569 - 600. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. D. CRANDALL and M. A. MATTHAY Alveolar Epithelial Transport . Basic Science to Clinical Medicine Am. J. Respir. Crit. Care Med., March 15, 2001; 163(4): 1021 - 1029. [Full Text]
|
|
|
|
|
|
X. Jiang, D. H. Ingbar, and S. M. O'Grady Selectivity properties of a Na-dependent amino acid cotransport system in adult alveolar epithelial cells Am J Physiol Lung Cell Mol Physiol, November 1, 2000; 279(5): L911 - L915. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
