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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1992-8-21
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pubmed:abstractText |
The presence of a Na+/Ca2+ exchanger in bovine adrenal chromaffin cells was demonstrated by measuring the efflux of 45Ca2+ which had been preloaded into cells by a brief depolarization. The efflux of 45Ca2+ was dependent on extracellular Na+ (Na+o); 45Ca2+ efflux was significantly decreased by replacing Na+o with N-methylglucamine (NMG), or Li+. Replacement of Na+o by NMG increased the resting intracellular Ca2+ concentration ([Ca2+]i) of freshly isolated chromaffin cells. This could be reversed by adding Na+, suggesting that Na+/Ca2+ exchanger activity was involved in maintaining [Ca2+]i at its resting level. The initial rate of Na(+)-dependent [Ca2+]i recovery after Ca2+ loading by depolarization was dependent on the level of [Ca2+]i. There was an apparent linear relationship between the activity of the Na+/Ca2+ exchanger and [Ca2+]i both in the presence and absence of Na+o. When cells were treated with other stimuli, including 10 microM DMPP or 40 mM caffeine, the ability of the stimulated cells to decrease [Ca2+]i was significantly reduced upon replacing Na+o with NMG. Our data show that the Na+/Ca2+ exchanger is one of the major pathways for regulating [Ca2+]i in chromaffin cells in both resting and stimulated states.
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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
|
pubmed:month |
Feb
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pubmed:issn |
0143-4160
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
13
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
99-106
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1633612-Adrenal Medulla,
pubmed-meshheading:1633612-Animals,
pubmed-meshheading:1633612-Caffeine,
pubmed-meshheading:1633612-Calcium,
pubmed-meshheading:1633612-Cattle,
pubmed-meshheading:1633612-Dimethylphenylpiperazinium Iodide,
pubmed-meshheading:1633612-Ion Exchange,
pubmed-meshheading:1633612-Kinetics,
pubmed-meshheading:1633612-Sodium
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pubmed:year |
1992
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pubmed:articleTitle |
Presence of Na+/Ca2+ exchange activity and its role in regulation of intracellular calcium concentration in bovine adrenal chromaffin cells.
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pubmed:affiliation |
Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, Republic of China.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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