Differential subcellular localization of ENaC subunits in mouse kidney in response to high- and low-Na diets

Details

Serval ID
serval:BIB_A99E492EB1C4
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Differential subcellular localization of ENaC subunits in mouse kidney in response to high- and low-Na diets
Journal
American Journal of Physiology. Renal Physiology
Author(s)
Loffing  J., Pietri  L., Aregger  F., Bloch-Faure  M., Ziegler  U., Meneton  P., Rossier  B. C., Kaissling  B.
ISSN
0363-6127
Publication state
Published
Issued date
08/2000
Peer-reviewed
Oui
Volume
279
Number
2
Pages
F252-8
Notes
In Vitro
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug
Abstract
Previous electrophysiological experiments on renal cortical collecting ducts indicated that dietary sodium intake and variations in aldosterone plasma levels regulate the abundance of functional epithelial Na channels (ENaC) in the apical plasma membrane. In mouse kidney we investigated by immunohistochemistry whether feeding for 3 wk a diet with high (3% Na) and low (0.05% Na) Na content influences the distribution pattern of ENaC. In mice of all experimental groups, ENaC was apparent in cells from the late portion of the distal convoluted tubule (DCT2) down to the medullary collecting duct (CD). In mice on a high-Na diet (plasma aldosterone: 40.8 +/- 2.0 ng/dl), the alpha-subunit was undetectable, and the beta- and gamma-ENaC were detected in the cytoplasm, but not in the apical plasma membrane of the cells. In contrast, in mice on a low-Na diet (plasma aldosterone: 93.6 +/- 9.3 ng/dl) all three ENaC subunits were displayed in the subapical cytoplasm and in the apical membrane of DCT2, connecting tubule (CNT), and, although less prominent, in cortical CD cells. Apical plasma membrane immunostaining progressively decreased along the cortical CD, simultaneously with increasing cytoplasmic staining for beta- and gamma-ENaC. Thus our data on mice adapted to moderately low and high Na intake suggest that regulation of ENaC function in vivo involves shifts of beta- and gamma-subunits from the cytoplasm to the apical plasma membrane and vice versa, respectively. The insertion of these subunits into the apical plasma membrane coincides with upregulation of the alpha-subunit and its insertion into the apical plasma membrane.
Keywords
Aldosterone/blood Animals Cell Membrane/metabolism *Diet, Sodium-Restricted Epithelial Sodium Channel Kidney/*metabolism Male Mice Mice, Inbred C57BL Natriuresis/physiology Protein Isoforms/metabolism Sodium Channels/*metabolism Sodium, Dietary/pharmacology Subcellular Fractions/*metabolism Tissue Distribution
Pubmed
Web of science
Create date
24/01/2008 13:00
Last modification date
20/08/2019 15:13
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