Linked Life Data

3591972

Source:http://linkedlifedata.com/resource/pubmed/id/3591972

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 2
pubmed:dateCreated
1987-7-15
pubmed:abstractText
Whereas action potential (AP) duration, area, and repolarization vary considerably, ventricular AP characteristics such as resting membrane potential, AP amplitude, and maximal upstroke velocity of phase 0 depolarization appear similar in a variety of mammalian species. As it has been shown that modifications of the thyroid state are associated with alterations in ventricular electrophysiological properties, we hypothesized that some variations in transmembrane potentials among mammalian species result in part from differences in the individual thyroid states. To test this hypothesis, we used standard microelectrode techniques to study ventricular APs in the dog, mole-rat, guinea pig, rat, mouse, and shrew, which encompass a wide range of thyroid states. In these species O2 consumption ranges from 0.38 (in the shrew) to 4.05 ml O2 X g-1 X h-1 (in the dog). We found that resting membrane potential and AP amplitude, duration, and area were inversely correlated with O2 consumption. The correlation coefficients between these parameters with O2 consumption were -0.92, -0.78, -0.91, and -0.92, respectively. We further tested the hypothesis in guinea pigs in which we modified the thyroid state in opposite directions by thyroxine administration and by propylthiouracil treatment. In the hypothyroid myocardium, AP duration (cycle length = 2,000 ms) markedly increased (P less than 0.001), whereas in the hyperthyroid myocardium, resting membrane potential and AP amplitude (P less than 0.01) and duration (P less than 0.001) decreased. We conclude that interspecies variations in ventricular electrophysiological properties can be correlated with the thyroid state, which may be an important determinant of these properties.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1265-74
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Ventricular electrophysiological properties: is interspecies variability related to thyroid state?
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.