Linked Life Data

12392892

Source:http://linkedlifedata.com/resource/pubmed/id/12392892

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2002-10-23
pubmed:abstractText
The different sodium channel currents (I(Na)) were reported in myocardium, neuron, and skeletal muscles. To study whether I(Na) is homogeneous within the heart, we applied whole-cell voltage clamp technique to evaluate fast voltage-gated I(Na) in atrial and ventricular myocytes isolated from guinea pig heart. It was found that the density of inward I(Na) was 50% greater at -35 mV in atrial (-42.6+/-2.9 pA/pF) than in ventricular (-27.5+/-1.8 pA/pF, P<0.01) myocytes. The half activation and inactivation voltages (V(0.5)) of I(Na) in atrial myocytes were shifted 4.5+/-0.2 and 9.6+/-0.3 mV negative to those of ventricular myocytes. Time constants for I(Na) activation (tau(m)) and inactivation (tau(h)) were twice as rapid in atrial as in ventricular myocytes. The tau(m) and tau(h) were 0.34+/-0.03 and 1.36+/-0.07 ms for atrial myocytes, and 0.69+/-0.05 and 3.27+/-0.23 ms for ventricular myocytes, respectively. Recovery of I(Na) from inactivation was slower in atrial than in ventricular myocytes, whereas the development of resting state inactivation was more rapid in atrial (tau=67.5+/-4.3 ms) than in ventricular (152.8+/-7.5 ms, P<0.01) myocytes. The results reveal marked heterogeneity of I(Na) in the density and biophysical properties in atrial and ventricular myocytes, and the study suggests the potential possibility of tissue specific cardiac sodium channel isoforms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-2828
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1185-94
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Heterogeneity of sodium current in atrial vs epicardial ventricular myocytes of adult guinea pig hearts.
pubmed:affiliation
Institute of Cardiovascular Science and Medicine/Department of Medicine, Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China. grli@hkucc.khu.hk
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't