Linked Life Data

12732270

Source:http://linkedlifedata.com/resource/pubmed/id/12732270

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2003-5-6
pubmed:abstractText
Stretch of the myocardium influences the shape and amplitude of the intracellular Ca(2+)([Ca(2+)](i)) transient. Under isometric conditions stretch immediately increases myofilament Ca(2+) sensitivity, increasing force production and abbreviating the time course of the [Ca(2+)](i) transient (the rapid response). Conversely, muscle shortening can prolong the Ca(2+) transient by decreasing myofilament Ca(2+) sensitivity. During the cardiac cycle, increased ventricular dilation may increase myofilament Ca(2+) sensitivity during diastolic filling and the isovolumic phase of systole, but enhance the decrease in myofilament Ca(2+) sensitivity during the systolic shortening of the ejection phase. If stretch is maintained there is a gradual increase in the amplitude of the Ca(2+) transient and force production, which takes several minutes to develop fully (the slow response). The rapid and slow responses have been reported in whole hearts and single myocytes. Here we review stretch-induced changes in [Ca(2+)](i) and the underlying mechanisms. Myocardial stretch also modifies electrical activity and the opening of stretch-activated channels (SACs) is often used to explain this effect. However, the myocardium has many ionic currents that are regulated by [Ca(2+)](i) and in this review we discuss how stretch-induced changes in [Ca(2+)](i) can influence electrical activity via the modulation of these Ca(2+)-dependent currents. Our recent work in single ventricular myocytes has shown that axial stretch prolongs the action potential. This effect is sensitive to either SAC blockade by streptomycin or the buffering of [Ca(2+)](i) with BAPTA, suggesting that both SACs and [Ca(2+)](i) are important for the full effects of axial stretch on electrical activity to develop.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0079-6107
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
81-95
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:articleTitle
Do stretch-induced changes in intracellular calcium modify the electrical activity of cardiac muscle?
pubmed:affiliation
School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, West Yorkshire, UK.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't