Linked Life Data

10860761

Source:http://linkedlifedata.com/resource/pubmed/id/10860761

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-8-9
pubmed:abstractText
Left ventricular remodeling after myocardial infarction is accompanied by electrical abnormalities that might predispose to rhythm disturbances. To get insight into the ionic mechanisms involved, we studied myocytes isolated from four different regions of the rat ventricles, 4-6 months after ligation of the left coronary artery. Using the whole-cell patch-clamp technique, we never observed T-type Ca(2+)current in both diseased and control hearts. In contrast, in 41 out of 78 cells isolated from 16 post-myocardial infarcted rats, analysed in the presence of 30 m m Na(+)ions, we found a tetrodotoxin (TTX)-resistant Na(+)current with quite variable amplitude in every investigated region. Albeit being resistant to 100 microM TTX, this Na(+)-dependent current was highly sensitive to lidocaine since 3 microM lidocaine induced about 65% tonic block. It was also inhibited by 5 microM nifedipine and 2 m m Co(2+), but was insensitive to 100 microM Ni(2+). The TTX-resistant Na(+)channel availability was shifted rightward by 25-30 mV with respect to TTX-sensitive Na(+)current; therefore, a large "window current" might flow in the voltage range from -70 to -20 mV. In conclusion, in late post-myocardial infarction, a Na(+)current with specific kinetics and pharmacology may provide inward charges in a critical range of membrane voltages that are able to alter action potential time course and trigger ventricular arrhythmia. These apparent new characteristics of the Na(+)channel might result in part from environmental changes during heart remodeling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2828
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1169-79
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Late post-myocardial infarction induces a tetrodotoxin-resistant Na(+)Current in rat cardiomyocytes.
pubmed:affiliation
Instituto de Cardiología y Cirugía Cardiovascular, La Habana, Cuba.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't