Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1998-12-14
pubmed:abstractText
The hypothesis that amiloride-sensitive Na+ channels (ENaC) are involved in cell volume regulation was tested. Anisosmotic ND-20 media (ranging from 70 to 450 mosM) were used to superfuse Xenopus oocytes expressing alpha beta gamma-rat ENaC (alpha beta gamma-rENaC). Whole cell currents were reversibly dependent on external osmolarity. Under conditions of swelling (70 mosM) or shrinkage (450 mosM), current amplitude decreased and increased, respectively. In contrast, there was no change in current amplitude of H2O-injected oocytes to the above osmotic insults. Currents recorded from alpha beta gamma-rENaC-injected oocytes were not sensitive to external Cl- concentration or to the K+ channel inhibitor BaCl2. They were sensitive to amiloride. The concentration of amiloride necessary to inhibit one-half of the maximal rENaC current expressed in oocytes (Ki; apparent dissociation constant) decreased in swollen cells and increased in shrunken oocytes. The osmotic pressure-induced Na+ currents showed properties similar to those of stretch-activated channels, including inhibition by Gd3+ and La3+, and decreased selectivity for Na+. alpha beta gamma-rENaC-expressing oocytes maintained a nearly constant cell volume in hypertonic ND-20. The present study is the first demonstration that alpha beta gamma-rENaC heterologously expressed in Xenopus oocytes may contribute to oocyte volume regulation following shrinkage.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1182-90
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Osmotic pressure regulates alpha beta gamma-rENaC expressed in Xenopus oocytes.
pubmed:affiliation
Department of Physiology and Biophysics, University of Alabama, Birmingham, Alabama 35294-0005, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.