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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1981-11-18
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pubmed:abstractText |
Regulation of passive potassium ion transport by the external calcium concentration and temperature was studied on cell cultures of 3T3 mouse cells and their DNA-virus transformed derivatives. Upon lowering of external calcium concentration, passive potassium efflux generally exhibits a sharp increase at about 0.1 mM. The fraction of calcium-regulated potassium efflux is largely independent of temperature in the cases of the transformed cells, but shows a sharp increase for 3T3 cells upon increasing temperature above 32 degrees C. In the same range of temperature, the 3T3 cells exhibit the phenomenon of high-temperature inactivation of the residual potassium efflux at 1 mM external calcium. At comparable cellular growth densities, the transformed cell lines do not show high-temperature inactivation of "residual" potassium efflux. These results are consistent with the notion of a decisive role of the internal K+ concentration in the cell-density dependent regulation of cell proliferation. In particular, the growth-inhibiting effect of lowering the external Ca2+ concentrations is considered as largely due to a rise of passive K+ efflux and a subsequent decrease of internal K+ concentration. The experimental data on the Ca2+ dependence of passive K+ flux are quantitatively described by a theoretical model based on the constant field relations including negative surface charges on the external face of the membrane, which cooperatively bind Ca2+ ions and may concomitantly undergo a lateral redistribution. The present evidence is consistent with acidic phospholipids as representing these negative surface charges.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:issn |
0022-2631
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
61
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
155-72
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:6268792-Animals,
pubmed-meshheading:6268792-Biological Transport,
pubmed-meshheading:6268792-Calcium,
pubmed-meshheading:6268792-Cell Transformation, Viral,
pubmed-meshheading:6268792-Cells, Cultured,
pubmed-meshheading:6268792-Mice,
pubmed-meshheading:6268792-Models, Biological,
pubmed-meshheading:6268792-Polyomavirus,
pubmed-meshheading:6268792-Potassium,
pubmed-meshheading:6268792-Simian virus 40,
pubmed-meshheading:6268792-Temperature,
pubmed-meshheading:6268792-Thermodynamics
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pubmed:year |
1981
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pubmed:articleTitle |
Regulation of passive potassium transport of normal and transformed 3T3 mouse cell cultures by external calcium concentration and temperature.
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pubmed:publicationType |
Journal Article
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