Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 2
pubmed:dateCreated
1995-9-1
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.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H203-14
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Cytoskeleton modulates gating of voltage-dependent sodium channel in heart.
pubmed:affiliation
Division of Cardiovascular Medicine, Henry Ford Heart and Vascular Institute, Detroit, Michigan 48202, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't