Linked Life Data

18223001

Source:http://linkedlifedata.com/resource/pubmed/id/18223001

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2008-3-13
pubmed:abstractText
The possible contribution of Na(+)-Ca(2+) exchange to the triggering of Ca(2+) release from the sarcoplasmic reticulum in ventricular cells remains unresolved. To gain insight into this issue, we measured the "trigger flux" of Ca(2+) crossing the cell membrane in rabbit ventricular myocytes with Ca(2+) release disabled pharmacologically. Under conditions that promote Ca(2+) entry via Na(+)-Ca(2+) exchange, internal [Na(+)] (10 mM), and positive membrane potential, the Ca(2+) trigger flux (measured using a fluorescent Ca(2+) indicator) was much greater than the Ca(2+) flux through the L-type Ca(2+) channel, indicating a significant contribution from Na(+)-Ca(2+) exchange to the trigger flux. The difference between total trigger flux and flux through L-type Ca(2+) channels was assessed by whole-cell patch-clamp recordings of Ca(2+) current and complementary experiments in which internal [Na(+)] was reduced. However, Ca(2+) entry via Na(+)-Ca(2+) exchange measured in the absence of L-type Ca(2+) current was considerably smaller than the amount inferred from the trigger flux measurements. From these results, we surmise that openings of L-type Ca(2+) channels increase [Ca(2+)] near Na(+)-Ca(2+) exchanger molecules and activate this protein. These results help to resolve seemingly contradictory results obtained previously and have implications for our understanding of the triggering of Ca(2+) release in heart cells under various conditions.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-10620297, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-11222287, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-1311127, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-1484286, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-15975978, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-1659502, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-2158147, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-2549177, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-7754384, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-8145151, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-8235594, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-8782114, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-9400385, http://linkedlifedata.com/resource/pubmed/commentcorrection/18223001-9649393
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1542-0086
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
L54-6
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Allosteric activation of Na+-Ca2+ exchange by L-type Ca2+ current augments the trigger flux for SR Ca2+ release in ventricular myocytes.
pubmed:publicationType
Letter, Research Support, N.I.H., Extramural