Linked Life Data

7518363

Source:http://linkedlifedata.com/resource/pubmed/id/7518363

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-8-18
pubmed:abstractText
Action potential duration is prolonged in ventricular hypertrophy induced by sustained pressure overload. Since the transient outward current (I(to)) is a major factor for determining action potential duration in rat ventricular cells, we used patch-clamp techniques to compare the characteristics of I(to) in normal and hypertrophied left ventricular cells of the rat. Left ventricular pressure overload was induced by partial ligation of the abdominal aorta for 4 to 6 weeks before study. Age-matched normal rats served as controls. Pressure overload increased the heart weight-to-body weight ratio by 47.7%. I(to) was significantly smaller in hypertrophied cells than in normal cells (20.0 +/- 1.3 versus 31.0 +/- 2.1 pA/pF, respectively, at a test potential of +60 mV; P < .001). There were no differences in the steady-state inactivation, the inactivation time course, and the time course of recovery from inactivation between normal and hypertrophied cells. At the single-channel level, there were no differences in the unitary current amplitude of the single I(to) channel between normal and hypertrophied cells, and the slope conductance was 13.7 picosiemens in normal cells and 13.4 picosiemens in hypertrophied cells. The maximum open-state probability, which was estimated from the ratio of the peak of the ensemble-averaged currents to the single-channel current amplitude, was similar for normal and hypertrophied cells (0.66 +/- 0.03 and 0.69 +/- 0.04, respectively, at a test potential of +40 mV; P = NS). We conclude that diminished I(to) contributes to action potential prolongation in hypertrophied ventricular cells from pressure-overloaded rat hearts. Reduced I(to) channel density may be responsible for the diminished whole-cell I(to).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
296-303
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Diminished transient outward currents in rat hypertrophied ventricular myocytes.
pubmed:affiliation
Department of Medicine, University of Miami, School of Medicine, FL 33101.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't