Linked Life Data

1359561

Source:http://linkedlifedata.com/resource/pubmed/id/1359561

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1326
pubmed:dateCreated
1992-12-3
pubmed:abstractText
Currents through delayed rectifier-type K+ channels in Schwann cells cultured from rabbit sciatic nerve were studied with patch-clamp techniques. When the internal and external solutions contained physiological concentrations of sodium, the amplitude of these outward currents declined as the cell was depolarized to potentials above about +40 mV, despite the increased driving force. This reduction in the amplitude of outward K+ currents was observed in many cells before the subtraction of leakage currents; it was also observed for ensemble currents recorded in outside-out patches. It was therefore not the result of a leak-subtraction artefact nor of inadequate voltage-clamp control. Several lines of evidence also suggested that it was not the result of the extracellular accumulation of K+. By contrast, when the Na+ ion concentration of the internal solution was nominally zero, the reduction in the amplitude of outward K+ currents at positive membrane potentials was not observed. The apparent amplitude of single-channel currents through two types of K+ channel was reduced by 30 mM internal Na+, apparently as the result of a rapid 'flickery' block. The results suggest that channel block by internal Na+ is largely responsible for the negative slope conductance seen in current-voltage plots of whole-cell K+ currents at positive membrane potentials. In addition, our analysis of single-channel currents suggests that the current-voltage curve for a delayed rectifier channel in rabbit Schwann cells (in the absence of internal Na+) is roughly linear with internal and external K+ concentrations of 140 mM and 5.6 mM, respectively.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0962-8452
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
249
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
309-16
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
On the block of outward potassium current in rabbit Schwann cells by internal sodium ions.
pubmed:affiliation
Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06510.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.