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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
24
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pubmed:dateCreated |
1985-11-29
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pubmed:abstractText |
The intracellular pH (pHi) changes resulting from chemotactic factor-induced activation of Na+/H+ exchange in isolated human neutrophils were characterized. Intracellular pH was measured from the equilibrium distribution of [14C]-5,5-dimethyloxazolidine-2,4-dione and from the fluorescence of 6-carboxyfluorescein. Exposure of cells to 0.1 microM N-formyl-methionyl-leucyl-phenylalanine (FMLP) in 140 mM Na+ medium at extracellular pH (pHo) 7.40 led to a rise in pHi along an exponential time course (rate coefficient approximately 0.55 min-1). By 10 min, a new steady-state pHi was reached (7.75-7.80) that was 0.55-0.60 units higher than the resting pHi of control cells (7.20-7.25). The initial rate of H+ efflux from the cells (approximately 15 meq/liter X min), calculated from the intrinsic intracellular buffering power of approximately 50 mM/pH, was comparable to the rate of net Na+ influx (approximately 17 meq/liter X min), an observation consistent with a 1:1 stoichiometry for Na+/H+ exchange. This counter-transport could be inhibited by amiloride (apparent Ki approximately 75 microM). When either the external ([Na+]o) or internal Na ([Na+]i) concentrations, pHo, or pHi were varied independently, the new steady-state [Na+]i and pHi values in FMLP-stimulated cells were those corresponding to a chemical equilibrium distribution of Na+ and H+ across the cell membrane. By analogy to other activated cells, these results indicate that an alkalinization of pHi in human neutrophils is mediated by a chemotactic factor-induced exchange of internal H+ for external Na+.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/6-carboxyfluorescein,
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Fluoresceins,
http://linkedlifedata.com/resource/pubmed/chemical/Indicators and Reagents,
http://linkedlifedata.com/resource/pubmed/chemical/Methylamines,
http://linkedlifedata.com/resource/pubmed/chemical/Monensin,
http://linkedlifedata.com/resource/pubmed/chemical/N-Formylmethionine...,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Hydrogen Antiporter,
http://linkedlifedata.com/resource/pubmed/chemical/trimethylamine
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pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
260
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
13248-55
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pubmed:dateRevised |
2004-11-17
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pubmed:meshHeading |
pubmed-meshheading:2997160-Amiloride,
pubmed-meshheading:2997160-Carrier Proteins,
pubmed-meshheading:2997160-Fluoresceins,
pubmed-meshheading:2997160-Humans,
pubmed-meshheading:2997160-Hydrogen-Ion Concentration,
pubmed-meshheading:2997160-Indicators and Reagents,
pubmed-meshheading:2997160-Intracellular Fluid,
pubmed-meshheading:2997160-Kinetics,
pubmed-meshheading:2997160-Methylamines,
pubmed-meshheading:2997160-Monensin,
pubmed-meshheading:2997160-N-Formylmethionine Leucyl-Phenylalanine,
pubmed-meshheading:2997160-Neutrophils,
pubmed-meshheading:2997160-Sodium,
pubmed-meshheading:2997160-Sodium-Hydrogen Antiporter
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pubmed:year |
1985
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pubmed:articleTitle |
Chemotactic factor-induced activation of Na+/H+ exchange in human neutrophils. II. Intracellular pH changes.
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pubmed:publicationType |
Journal Article
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