Linked Life Data

9160874

Source:http://linkedlifedata.com/resource/pubmed/id/9160874

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1997-7-17
pubmed:abstractText
This study demonstrates the inverse relationship between extracellular free calcium ([Ca(o)]f) and intracellular sodium ([Na(i)]) in isolated perfused rat hearts and thus supports the role of [Na(i)] in the "calcium paradox". It also shows that the extent of the increase in [Na(i)] (delta[Na(i)]), and the extent of the decrease in left ventricular developed pressure (deltaLVDP) in isolated perfused rat hearts, induced by pacing, is modulated by [Ca(o)]f. At low (0.24 mM) as well as normal (1.15 mM) [Ca(o)]f, [Na(i)] increased with pacing, progressively and significantly (P<0.01 and P<0.05, respectively), reaching a maximum of 12.56 +/- 0.46 and 9.22 +/- 0.16 mM at 500 beats/min, respectively. At high [Ca(o)]f (2.2 mM), however, no pacing-induced increase in [Na(i)] was observed. Simultaneously, within the pacing range of 250-500 beats/min, the interval-force relationship was negative for all [Ca(o)]f. With decreasing [Ca(o)]f, a gradually increasing delta[Na(i)] was induced. We hypothesise that a [Ca(o)]f-dependent Na-Ca exchanger activity modulates Na+ uptake, and thus baseline [Na(i)]. During incremental pacing, the increase in pacing rate induces a [Ca(o)]f-dependent delta[Na(i)], which may interact further with the sarcolemmal Na-Ca exchanger activity. As a result, both baseline [Na(i)] and the pacing-induced, [Ca(o)]f-dependent delta[Na(i)] modulate the net Ca2+ uptake, and thus SR Ca, in a manner that results in a modulated left ventricular force development.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2828
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1225-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
The modulation of pacing-induced changes in intracellular sodium levels by extracellular Ca2+ in isolated perfused rat hearts.
pubmed:affiliation
Department of Biochemistry & Molecular Genetics, University of Alabama at Birmingham, 35294-0006, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.