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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
1995-8-4
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pubmed:abstractText |
Ca2+ release from the sarcoplasmic reticulum was studied in voltage-clamped guinea-pig atrial myocytes. Cells were dialysed with a pipette solution containing the Ca2+ indicator 1- [2-amino-5-(6-carboxyindol-2-yl) phenoxy]-2-(2'-amino-5'-methylphenoxy) ethane-N,N,N',N'-tetraacetic acid] (Indo-1, 100 microM) and as main anion either chloride or the low-affinity Ca2+ buffer citrate. Intracellular Ca2+ transients (Cai transients) were elicited by depolarizations from a holding potential of -50 mV. In chloride-dialysed cells, Cai transients showed a bell-shaped dependence on the amplitude of the depolarizing pulse. In citrate-dialysed cells, membrane depolarizations were associated with a small rise in [Ca2+]i. These small changes in [Ca2+]i were either followed by a large Cai transient or failed to induce large changes in [Ca2+]i. The peak amplitude of the large Cai transient did not vary with the amplitude of the depolarizing pulse. These results demonstrate that in the presence of intracellular chloride, Ca2+ release in atrial cells is a graded process triggered by Ca2+ influx. Using citrate as the main intracellular anoin, Ca2+ release triggered by Ca2+ entry was no longer graded but occurred in a regenerative manner. The results are discussed in terms of two models in which citrate, affects the spatial distribution of [Ca2+]i or the loading state of the sarcoplasmic reticulum.
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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/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Chlorides,
http://linkedlifedata.com/resource/pubmed/chemical/Citrates,
http://linkedlifedata.com/resource/pubmed/chemical/Citric Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0031-6768
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
429
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
797-804
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:7603833-Animals,
pubmed-meshheading:7603833-Calcium,
pubmed-meshheading:7603833-Chlorides,
pubmed-meshheading:7603833-Citrates,
pubmed-meshheading:7603833-Citric Acid,
pubmed-meshheading:7603833-Dialysis,
pubmed-meshheading:7603833-Electric Conductivity,
pubmed-meshheading:7603833-Guinea Pigs,
pubmed-meshheading:7603833-Heart Atria,
pubmed-meshheading:7603833-Kinetics,
pubmed-meshheading:7603833-Membrane Potentials,
pubmed-meshheading:7603833-Myocardium,
pubmed-meshheading:7603833-Patch-Clamp Techniques,
pubmed-meshheading:7603833-Sarcoplasmic Reticulum,
pubmed-meshheading:7603833-Sodium
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pubmed:year |
1995
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pubmed:articleTitle |
Intracellular citrate induces regenerative calcium release from sarcoplasmic reticulum in guinea-pig atrial myocytes.
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pubmed:affiliation |
Laboratory of Physiology, University of Leuven, Belgium.
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pubmed:publicationType |
Journal Article
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