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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1246
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pubmed:dateCreated |
1986-5-19
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pubmed:abstractText |
Large outward currents are recorded with the whole-cell patch-clamp technique on depolarization of rabbit cultured fibroblasts. Our findings suggest that these outward currents consist of two voltage-dependent components, one of which also depends on cytoplasmic calcium concentration. Total replacement of external Cl- by the large anion ascorbate does not affect the amplitude of the currents, indicating that both components must be carried by K+. Consistent with these findings with whole-cell currents, in single channel recordings from fibroblasts we found that most patches contain high-conductance potassium-selective channels whose activation depends on both membrane potential and the calcium concentration at the cytoplasmic surface of the membrane. In a smaller number of patches, a second population of high-conductance calcium-independent potassium channels is observed having different voltage-dependence. The calcium- and voltage-dependence suggest that these two channels correspond with the two components of outward current seen in the whole-cell recordings. The single channel conductance of both channels in symmetrical KCl (150 mM) is 260-270 pS. Both channels are highly selective for K+ over both Na+ and Cl-. The conductance of the channels when outward current is carried by Rb+ is considerably smaller than when it is carried by K+. Some evidence is adduced to support the hypothesis that these potassium channel populations may be involved in the control of cell proliferation.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/4-Aminopyridine,
http://linkedlifedata.com/resource/pubmed/chemical/Aminopyridines,
http://linkedlifedata.com/resource/pubmed/chemical/Amphibian Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Chlorides,
http://linkedlifedata.com/resource/pubmed/chemical/Ion Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Saxitoxin,
http://linkedlifedata.com/resource/pubmed/chemical/Tetraethylammonium Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Tetrodotoxin,
http://linkedlifedata.com/resource/pubmed/chemical/saxitoxin-binding protein, Rana...
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0080-4649
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
22
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pubmed:volume |
227
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1-16
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2421292-4-Aminopyridine,
pubmed-meshheading:2421292-Aminopyridines,
pubmed-meshheading:2421292-Amphibian Proteins,
pubmed-meshheading:2421292-Animals,
pubmed-meshheading:2421292-Calcium,
pubmed-meshheading:2421292-Carrier Proteins,
pubmed-meshheading:2421292-Cells, Cultured,
pubmed-meshheading:2421292-Chlorides,
pubmed-meshheading:2421292-Fibroblasts,
pubmed-meshheading:2421292-Ion Channels,
pubmed-meshheading:2421292-Membrane Potentials,
pubmed-meshheading:2421292-Potassium,
pubmed-meshheading:2421292-Rabbits,
pubmed-meshheading:2421292-Rats,
pubmed-meshheading:2421292-Rats, Inbred Strains,
pubmed-meshheading:2421292-Saxitoxin,
pubmed-meshheading:2421292-Tetraethylammonium Compounds,
pubmed-meshheading:2421292-Tetrodotoxin
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pubmed:year |
1986
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pubmed:articleTitle |
Ion channels in rabbit cultured fibroblasts.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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