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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1982-5-21
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pubmed:abstractText |
Confluent monolayer cultures of the differentiated kidney epithelial cell line, Madin-Darby canine kidney cells (MDCK), have been used to study ion transport mechanisms involved in transepithelial transport. We have investigated the previously reported K+-stimulation of 22Na+ uptake by confluent monolayers of Na+ depleted cells (Rindler, M. J., Taub, M., and Saier, M. H., Jr. (1979) J. Biol. Chem. 254, 11431-11439). This component of Na+ uptake was insensitive to ouabain and amiloride, but was strongly inhibited by furosemide or bumetanide. Ouabain-insensitive 86Rb+ uptake was also inhibitable by furosemide or bumetanide and stimulated by extracellular Na+. The synergistic effect of Na+ and 86Rb+ uptake and K+ on 22Na+ uptake was reflected by an increase in the apparent Vmax and a decrease in the apparent Km as the concentration of the other cation was increased. The extrapolated Km for either 86Rb+ or 22Na+ uptake in the absence of the other cation was 30 mM while the Km in the presence of a saturating concentration of the other cation was 9 mM. The absolute Vmax values for 22Na+ and 86Rb+ uptake suggest a cotransport system with a stoichiometry of 2Na+:3K+. However, because of the experimental design, the actual ratio may be closer to 1:1. Competition with, and stimulation by, a variety of unlabeled cations indicated that Na+ could be partially replaced by Li+, while K+ could be fully replaced by Rb+ and partially replaced by NH4+ and CS+. Uptake by this system was dependent upon cellular ATP. Reduction of intracellular ATP to 3% of normal abolished both K+-stimulated 22Na+ uptake and Na+-stimulated 86Rb+ uptake.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Bumetanide,
http://linkedlifedata.com/resource/pubmed/chemical/Furosemide,
http://linkedlifedata.com/resource/pubmed/chemical/Ouabain,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Rubidium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Potassium-Exchanging ATPase
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
10
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pubmed:volume |
257
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2254-9
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:6277889-Amiloride,
pubmed-meshheading:6277889-Animals,
pubmed-meshheading:6277889-Biological Transport, Active,
pubmed-meshheading:6277889-Bumetanide,
pubmed-meshheading:6277889-Cell Line,
pubmed-meshheading:6277889-Dogs,
pubmed-meshheading:6277889-Furosemide,
pubmed-meshheading:6277889-Kidney,
pubmed-meshheading:6277889-Kinetics,
pubmed-meshheading:6277889-Ouabain,
pubmed-meshheading:6277889-Potassium,
pubmed-meshheading:6277889-Rubidium,
pubmed-meshheading:6277889-Sodium,
pubmed-meshheading:6277889-Sodium-Potassium-Exchanging ATPase
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pubmed:year |
1982
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pubmed:articleTitle |
(Na+,K+)-cotransport in the Madin-Darby canine kidney cell line. Kinetic characterization of the interaction between Na+ and K+.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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