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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4 Pt 2
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pubmed:dateCreated |
1997-12-10
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pubmed:abstractText |
The aim of this study was to investigate modulation of voltage-dependent steady-state activation and availability from inactivation of the cardiac Na+ channel by the cytoskeleton. As an experimental approach, we used long-lasting monitoring [63 +/- 5 (SE) min] of the half-point potentials of the steady-state availability curve (V(1/2A)) and normalized conductance curve (V(1/2G)) in 116 rat ventricular cardiomyocytes by whole cell patch clamp at 22-24 degrees C. Both half-point potentials shifted in the negative direction with time as an exponentially saturating change, with the shift of V(1/2G) being smaller and faster. An F-actin disrupter, cytochalasin D (Cyto-D, 20 microM), accelerated the rate of the V(1/2A) shift but decreased the range of the V(1/2G) shift. An F-actin stabilizer, phalloidin (100 microM), temporarily (for 28.2 +/- 2.2 min, n = 15) prevented the V(1/2A) shift but did not influence the V(1/2G) shift. The best fit for the V(1/2G)-V(1/2A) relationship in untreated cells (1,021 data points measured in 51 cells) was a second-degree (2.06) power function. Cytoskeleton-directed agents modified the relationship. In Cyto-D-treated cells, the V(1/2G)-V(1/2A) relationship was shifted (by 2.5 mV) toward positive V(1/2G). On the contrary, a microtubule stabilizer, taxol (100 microM), shifted the relationship toward negative V(1/2G) (by 12.2 mV). We conclude that coupling between availability and activation is modulated by F-actin-based and microtubular cytoskeleton.
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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 |
Oct
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
273
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
H1832-40
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:9362250-Animals,
pubmed-meshheading:9362250-Cytochalasin D,
pubmed-meshheading:9362250-Cytoskeleton,
pubmed-meshheading:9362250-Electric Conductivity,
pubmed-meshheading:9362250-Homeostasis,
pubmed-meshheading:9362250-Models, Cardiovascular,
pubmed-meshheading:9362250-Myocardium,
pubmed-meshheading:9362250-Paclitaxel,
pubmed-meshheading:9362250-Patch-Clamp Techniques,
pubmed-meshheading:9362250-Phalloidine,
pubmed-meshheading:9362250-Rats,
pubmed-meshheading:9362250-Rats, Sprague-Dawley,
pubmed-meshheading:9362250-Sodium Channels
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pubmed:year |
1997
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pubmed:articleTitle |
Cytoskeleton modulates coupling between availability and activation of cardiac sodium channel.
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pubmed:affiliation |
Division of Cardiovascular Medicine, Henry Ford Heart and Vascular Institute, Detroit, Michigan 48202-2689, USA.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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