Source:http://linkedlifedata.com/resource/pubmed/id/16845488
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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1-2
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pubmed:dateCreated |
2007-1-23
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pubmed:abstractText |
Isolated hepatocytes release 2-3 nmol Mg2+/mg protein or approximately 10% of the total cellular Mg2+ content within 2 minutes from the addition of agonists that increase cellular cAMP, for example, isoproterenol (ISO). During Mg2+ release, a quantitatively similar amount of Ca2+ enters the hepatocyte, thus suggesting a stoichiometric exchange ratio of 1 Mg2+:1Ca2+. Calcium induced Mg2+ extrusion is also observed in apical liver plasma membranes (aLPM), in which the process presents the same 1 Mg2+:1Ca2+ exchange ratio. The uptake of Ca2+ for the release of Mg2+ occurs in the absence of significant changes in Deltapsi as evidenced by electroneutral exchange measurements with a tetraphenylphosphonium (TPP+) electrode or 3H-TPP+. Collapsing the Deltapsi by high concentrations of TPP+ or protonophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) does not inhibit the Ca2+-induced Mg2+ extrusion in cells or aLPM. Further, the process is strictly unidirectional, serving only in Ca2+ uptake and Mg2+ release. These data demonstrate the operation of an electroneutral Ca2+/Mg2+ exchanger which represents a novel pathway for Ca2+ accumulation in liver cells following adrenergic receptor stimulation.
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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/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Collagenases,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Onium Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Organophosphorus Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/tetraphenylphosphonium
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0300-8177
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
295
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
241-7
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pubmed:dateRevised |
2007-12-3
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pubmed:meshHeading |
pubmed-meshheading:16845488-Animals,
pubmed-meshheading:16845488-Calcium,
pubmed-meshheading:16845488-Cell Membrane,
pubmed-meshheading:16845488-Cell Polarity,
pubmed-meshheading:16845488-Cell Separation,
pubmed-meshheading:16845488-Collagenases,
pubmed-meshheading:16845488-Hepatocytes,
pubmed-meshheading:16845488-Liver,
pubmed-meshheading:16845488-Magnesium,
pubmed-meshheading:16845488-Male,
pubmed-meshheading:16845488-Membrane Potentials,
pubmed-meshheading:16845488-Membrane Transport Proteins,
pubmed-meshheading:16845488-Onium Compounds,
pubmed-meshheading:16845488-Organophosphorus Compounds,
pubmed-meshheading:16845488-Rats,
pubmed-meshheading:16845488-Rats, Sprague-Dawley
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pubmed:year |
2007
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pubmed:articleTitle |
Mg2+ release coupled to Ca2+ uptake: a novel Ca 2+ accumulation mechanism in rat liver.
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pubmed:affiliation |
Department Physiology and Biophysics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA. cml5@po.cwru.edu
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pubmed:publicationType |
Journal Article,
Research Support, N.I.H., Extramural
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