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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
2
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pubmed:dateCreated |
1974-2-14
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pubmed:abstractText |
1. In resealed human red cells loaded with Ca-EGTA buffer solutions it was found that the intracellular free Ca(2+) concentration for half saturation of the Ca transport system (which pumps Ca out of the cell) is equal to or smaller than 4 x 10(-6)M and thus closely agrees with the dissociation constant of the Ca + Mg activated membrane ATPase.2. The maximal rate of Ca transport from resealed cells to medium was found to be 0.148 +/- 0.009 mumole/ml. cells.min at 28 degrees C.3. The rate of Ca transport was unaffected by a variation of the extracellular Ca(2+) concentration from 3.10(-7) to 5.10(-3)M.4. Evidence is presented making it probable that the stoichiometric relation between Ca transported and ATP hydrolysed is 1:1 rather than 2:1.5. As the Ca transport is quite rapid even at half saturation and the passive leak for Ca negligible in intact cells it can be predicted that the steady-state cellular Ca(2+) concentration must be low, most probably less than 10(-6) mumole/ml. cells. Transport from cells containing 5.10(-7) mumole/ml. into blood plasma is thermodynamically compatible with the normal plasma Ca(2+) concentration and the normal cellular ATP, ADP and P(i) content.6. Treatment with the mercurial PCMBS in the cold for 15 hr allows to load red cells with 1 mumole Ca/ml. cells without destroying their ability to transport Ca after removal of the mercurial.7. It is shown that at high cellular Ca concentrations (0.1-3 mumole/ml. cells) about 50% of the total is free Ca(2+) on account of binding mainly to dialysable cell constituents.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-13084520,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-13628584,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-13725019,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-14179458,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-14236644,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4238381,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4250576,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4258479,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4258480,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4261006,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4264462,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4266093,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4304202,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4306542,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-4996367,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-5357189,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-5498486,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-5543418,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-5961668,
http://linkedlifedata.com/resource/pubmed/commentcorrection/4271735-6065891
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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 |
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0022-3751
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
235
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
551-69
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pubmed:dateRevised |
2010-9-13
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pubmed:meshHeading |
pubmed-meshheading:4271735-Adenosine Triphosphatases,
pubmed-meshheading:4271735-Benzenesulfonates,
pubmed-meshheading:4271735-Biological Transport, Active,
pubmed-meshheading:4271735-Calcium,
pubmed-meshheading:4271735-Cell Membrane,
pubmed-meshheading:4271735-Erythrocytes,
pubmed-meshheading:4271735-Humans,
pubmed-meshheading:4271735-Mathematics,
pubmed-meshheading:4271735-Mercury,
pubmed-meshheading:4271735-Organometallic Compounds,
pubmed-meshheading:4271735-Temperature,
pubmed-meshheading:4271735-Thermodynamics
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pubmed:year |
1973
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pubmed:articleTitle |
Dependence on calcium concentration and stoichiometry of the calcium pump in human red cells.
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pubmed:publicationType |
Journal Article,
In Vitro
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