Hypoxia downregulates expression and activity of epithelial sodium channels in rat alveolar epithelial cells.

@article{Plans1997HypoxiaDE,
  title={Hypoxia downregulates expression and activity of epithelial sodium channels in rat alveolar epithelial cells.},
  author={Carole Plan{\`e}s and Brigitte Escoubet and Marcel Blot-Chabaud and G{\'e}rard Friedlander and Nicolette Farman and Christine Cl{\'e}rici},
  journal={American journal of respiratory cell and molecular biology},
  year={1997},
  volume={17 4},
  pages={
          508-18
        }
}
Decrease in alveolar oxygen tension may induce acute lung injury with pulmonary edema. We investigated whether, in alveolar epithelial cells, expression and activity of epithelial sodium (Na) channels and Na,K-adenosine triphosphatase, the major components of transepithelial Na transport, were regulated by hypoxia. Exposure of cultured rat alveolar cells to 3% and 0% O2 for 18 h reduced Na channel activity estimated by amiloride-sensitive 22Na influx by 32% and 67%, respectively, whereas 5% O2… 
Hypoxia reduces alveolar epithelial sodium and fluid transport in rats: reversal by beta-adrenergic agonist treatment.
TLDR
The dramatic increase of ALC with beta(2)-agonist therapy indicates that the decrease of transepithelial Na and fluid transport during hypoxia is rapidly reversible, a finding of major clinical significance.
Hypoxia and β2-Agonists Regulate Cell Surface Expression of the Epithelial Sodium Channel in Native Alveolar Epithelial Cells*
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It is established that hypoxia-induced inhibition of amiloride-sensitive sodium channel activity is mediated by decreased apical expression of ENaC subunits and that β2-agonists reverse this effect by enhancing the insertion of ENc subunits into the membrane of hypoxic alveolar epithelial cells.
Hypoxia decreases proteins involved in epithelial electrolyte transport in A549 cells and rat lung.
TLDR
Results indicate a slow decrease in the amount of Na-transporting proteins in alveolar epithelial cells during exposure to hypoxia that also occurs in vivo in lungs from hypoxic animals.
The role of hypoxia-induced modulation of alveolar epithelial Na+- transport in hypoxemia at high altitude
TLDR
Results indicate that a HIF-2α-dependent decrease in Na+-transport in hypoxic alveolar epithelium decreases alveolars reabsorption, which might further enhance hypoxic pulmonary vasoconstriction and cause HAPE.
Hypoxia upregulates activity and expression of the glucose transporter GLUT1 in alveolar epithelial cells.
TLDR
It is demonstrated that AEC increased glucose transport in response to hypoxia by regulating GLUT1 gene-encoding protein through the activation of an HIF, the nature of which remains to be elucidated.
Hypoxia reversibly inhibits epithelial sodium transport but does not inhibit lung ENaC or Na-K-ATPase expression.
TLDR
It is concluded that subacute exposure to moderate hypoxia reversibly impairs airway epithelial sodium transport and lung Na,K-ATPase activity but that those changes are not due to changes in the lung expression of sodium-transporting proteins.
Dexamethasone prevents transport inhibition by hypoxia in rat lung and alveolar epithelial cells by stimulating activity and expression of Na+-K+-ATPase and epithelial Na+ channels.
TLDR
It is indicated that DEX prevents inhibition of alveolar reabsorption by hypoxia and stimulates the expression of Na transporters even when it is applied in Hypoxia.
Hypoxia decreases active Na transport across primary rat alveolar epithelial cell monolayers.
TLDR
Exposure to hypoxia inhibits alveolar epithelial Na reabsorption by reducing the rates of both apical amiloride-sensitive Na entry and basolateral Na extrusion.
Alveolar epithelial ion and fluid transport: Hypoxia decreases active Na transport across primary rat alveolar epithelial cell monolayers
Hypoxia has been reported to inhibit activity and expression of ion transporters of alveolar epithelial cells. This study extended those observations by investigating the mechanisms underlying
β-Adrenergic Receptor Stimulation and Adenoviral Overexpression of Superoxide Dismutase Prevent the Hypoxia-mediated Decrease in Na,K-ATPase and Alveolar Fluid Reabsorption*
TLDR
The decrease in AFR was associated with a decrease in Na,K-ATPase activity and protein abundance in the basolateral membranes from peripheral lung tissue of hypoxic rats and β-Adrenergic agonists restored AFR in rats exposed to 8% O2.
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