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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1 Pt 2
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pubmed:dateCreated |
1995-9-1
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pubmed:abstractText |
To investigate the role of the cytoskeleton in cardiac Na+ channel gating, the action of cytochalasin D (Cyto-D), an agent that interferes with actin polymerization, was studied by whole cell voltage clamp and cell-attached and inside-out patches from rat and rabbit ventricular cardiac myocytes. Cyto-D (20-40 microM) reduced whole cell peak Na+ current by 20% within 12 min and slowed current decay without affecting steady-state voltage-dependent availability or recovery from inactivation. Brief treatments (< 10-15 min) of cell-attached patches by Cyto-D (20 microM) in the bath induced short bursts of Na+ channel openings and prolonged decays of ensemble-averaged currents. Bursting of the Na+ channel was more pronounced when the cell suspension was pretreated with Cyto-D (20 microM) for 1 h before seal formation. Application of Cyto-D on the cytoplasmic side of inside-out patches resulted in more dramatic gating changes. Peak open probability was reduced by > 50% within 20 min, and long bursts of openings occurred. Washout of Cyto-D did not restore ensemble-averaged current amplitude, but burst duration decreased toward control values. Cyto-D also induced an additional slower component to open and closed times. These results suggest that Cyto-D, through effects on cytoskeleton, induced cardiac Na+ channels to enter a mode characterized by a lower peak open probability but a greater persistent activity as if the inactivation rate was slowed. The cytoskeleton, in addition to localizing integral membrane proteins, apparently also plays a role in regulating specific detailed functions of integral membrane proteins such as the gating of Na+ channels.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
269
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
H203-14
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:7631850-Animals,
pubmed-meshheading:7631850-Cytochalasin D,
pubmed-meshheading:7631850-Cytoskeleton,
pubmed-meshheading:7631850-Electrophysiology,
pubmed-meshheading:7631850-Ion Channel Gating,
pubmed-meshheading:7631850-Myocardium,
pubmed-meshheading:7631850-Rabbits,
pubmed-meshheading:7631850-Rats,
pubmed-meshheading:7631850-Reaction Time,
pubmed-meshheading:7631850-Sodium Channels
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pubmed:year |
1995
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pubmed:articleTitle |
Cytoskeleton modulates gating of voltage-dependent sodium channel in heart.
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pubmed:affiliation |
Division of Cardiovascular Medicine, Henry Ford Heart and Vascular Institute, Detroit, Michigan 48202, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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