Linked Life Data

12690465

Source:http://linkedlifedata.com/resource/pubmed/id/12690465

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-4-11
pubmed:abstractText
Zn(2+) (1-1,000 microM) applied to the apical side of polarized A6 epithelia inhibits Na(+) transport, as reflected in short-circuit current and conductance measurements. The Menten equilibrium constant for Zn(2+) inhibition was 45 microM. Varying the apical Na(+) concentration, we determined the equilibrium constant of the short-circuit current saturation (34.9 mM) and showed that Zn(2+) inhibition is non-competitive. A similar effect was observed in Xenopus oocytes expressing alphabetagammarENaC (alpha-, beta-, and gamma-subunits of the rat epithelial Na(+) channel) in the concentration range of 1-10 microM Zn(2+), while at 100 microM Zn(2+) exerted a stimulatory effect. The analysis of the voltage dependence of the steady-state conductance revealed that the inhibitory effect of Zn(2+) was due mainly to a direct pore block and not to a change in surface potential. The equivalent gating charge of ENaC, emerging from these data, was 0.79 elementary charges, and was not influenced by Zn(2+). The stimulatory effect of high Zn(2+) concentrations could be reproduced by intra-oocyte injection of Zn(2+) (approximately 10 microM), which had no direct effect on the amiloride-sensitive conductance, but switched the effect of extracellular Zn(2+) from inhibition to activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
446
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
69-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Zinc is a voltage-dependent blocker of native and heterologously expressed epithelial Na+ channels.
pubmed:affiliation
Department of Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, 76201 Bucharest, Romania.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't