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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2001-5-25
pubmed:abstractText
We studied the effect of titin-based passive force on the length dependence of activation of cardiac myocytes to explore whether titin may play a role in the generation of systolic force. Force-pCa relations were measured at sarcomere lengths (SLs) of 2.0 and 2.3 microm. Passive tension at 2.3 microm SL was varied from approximately 1 to approximately 10 mN/mm(2) by adjusting the characteristics of the stretch imposed on the passive cell before activation. Relative to 2.0 microm SL, the force-pCa curve at 2.3 microm SL and low passive tension showed a leftward shift (pCa(50) [change in pCa at half-maximal activation]) of 0.09+/-0.02 pCa units while at 2.3 microm SL and high passive tension the shift was increased to 0.25+/-0.03 pCa units. Passive tension also increased pCa(50) at reduced interfilament lattice spacing achieved with dextran. We tested whether titin-based passive tension influences the interfilament lattice spacing by measuring the width of the myocyte and by using small-angle x-ray diffraction of mouse left ventricular wall muscle. Cell width and interfilament lattice spacing varied inversely with passive tension, in the presence and absence of dextran. The passive tension effect on length-dependent activation may therefore result from a radial titin-based force that modulates the interfilament lattice spacing.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1524-4571
pubmed:author
pubmed:issnType
Electronic
pubmed:day
25
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1028-35
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:11375272-Actin Cytoskeleton, pubmed-meshheading:11375272-Animals, pubmed-meshheading:11375272-Calcium, pubmed-meshheading:11375272-Cells, Cultured, pubmed-meshheading:11375272-Dextrans, pubmed-meshheading:11375272-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:11375272-Heart Ventricles, pubmed-meshheading:11375272-Isometric Contraction, pubmed-meshheading:11375272-Mice, pubmed-meshheading:11375272-Muscle Proteins, pubmed-meshheading:11375272-Myocardial Contraction, pubmed-meshheading:11375272-Myocardium, pubmed-meshheading:11375272-Osmolar Concentration, pubmed-meshheading:11375272-Protein Kinases, pubmed-meshheading:11375272-Sarcomeres, pubmed-meshheading:11375272-Stress, Mechanical, pubmed-meshheading:11375272-Trypsin, pubmed-meshheading:11375272-X-Ray Diffraction
pubmed:year
2001
pubmed:articleTitle
Titin-based modulation of calcium sensitivity of active tension in mouse skinned cardiac myocytes.
pubmed:affiliation
Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, Pullman, WA 88164, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't