Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-4-16
pubmed:abstractText
The mechanism of action of the lidocaine derivative transcainide was examined using [3H]batrachotoxinin 20 alpha-benzoate, which binds specifically to and stabilizes activated states of the sodium channel. Transcainide (IC50 0.3 microM) inhibited equilibrium [3H]batrachotoxinin binding to sodium channels present on freshly isolated rat cardiac myocytes. Scatchard analysis of [3H]batrachotoxinin binding showed that transcainide both reduced maximal binding and altered the KD for [3H]batrachotoxinin binding, indicating noncompetitive, allosteric inhibition. Inhibition by transcainide of [3H]batrachotoxinin binding was reversible within 60 min. We used state-dependent [3H]batrachotoxinin binding assays to examine whether transcainide preferentially binds to activated or nonactivated sodium channels. Transcainide had little effect on the k-1 of [3H]batrachotoxinin even at concentrations 1000-fold greater than its IC50, indicating low affinity of transcainide for activated channels. However, transcainide decreased the k + 1 of [3H]batrachotoxinin at a concentration very close to its IC50 concentration for inhibiting equilibrium [3H]batrachotoxinin binding. The results are discussed in terms of a model in which transcainide inhibits [3H]batrachotoxinin binding by binding specifically to and stabilizing a nonactivated state of the cardiac sodium channel.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
203
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
51-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Transcainide: biochemical evidence for state-dependent interaction with the class I antiarrhythmic drug receptor.
pubmed:affiliation
Department of Medicine, University of Calgary, Alberta, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't