Linked Life Data

18024719

Source:http://linkedlifedata.com/resource/pubmed/id/18024719

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-3-10
pubmed:abstractText
Transepithelial alveolar sodium (Na+) transport mediated by the amiloride-sensitive epithelial sodium channel (ENaC) constitutes the driving force for removal of fluid from the alveolar space. To define the role of the beta-ENaC subunit in vivo in the mature lung, we studied a previously established mouse strain harboring a disruption of the beta-ENaC gene locus resulting in low levels of beta-ENaC mRNA expression. Real-time RT-PCR experiments confirmed that beta-ENaC mRNA levels were decreased by >90% in alveolar epithelial cells from homozygous mutant (m/m) mice. beta-ENaC protein was undetected in lung homogenates from m/m mice by Western blotting, but alpha- and gamma-ENaC proteins were increased by 83% and 45%, respectively, compared with wild-type (WT) mice. At baseline, Na+-driven alveolar fluid clearance (AFC) was significantly reduced by 32% in m/m mice. Amiloride at the concentration 1 mM inhibited AFC by 75% and 34% in WT and m/m mice, respectively, whereas a higher concentration (5 mM) induced a 75% inhibition of AFC in both groups. The beta2-agonist terbutaline significantly increased AFC in WT but not in m/m mice. These results show that despite the compensatory increase in alpha- and gamma-ENaC protein expression observed in mutant mouse lung, low expression of beta-ENaC results in a moderate impairment of baseline AFC and in decreased AFC sensitivity to amiloride, suggesting a possible change in the stoichiometry of ENaC channels. Finally, adequate beta-ENaC expression appears to be required for AFC stimulation by beta2-agonists.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1040-0605
pubmed:author
pubmed:issnType
Print
pubmed:volume
294
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
L409-16
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Low expression of the beta-ENaC subunit impairs lung fluid clearance in the mouse.
pubmed:affiliation
INSERM U773, CRB3, Université Denis Diderot-Paris 7, 16 rue Henri Huchard, 75018 Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't