Linked Life Data

1703597

Source:http://linkedlifedata.com/resource/pubmed/id/1703597

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1991-3-1
pubmed:abstractText
We compared the effects of a low (0.09 microgram/ml) concentration of propranolol expected to produce only beta-adrenoceptor blockade and a high concentration (0.9 microgram/ml) expected to produce additional direct local anesthetic-like electrophysiological effects on basic and premature action potentials. Both isolated dog cardiac Purkinje and ventricular muscle fibers were examined using conventional microelectrode techniques. The low concentration of propranolol produced no significant electrophysiological change in either fiber type. The high concentration of propranolol shortened the action potential duration and refractoriness while decreasing the maximal upstroke velocity (Vmax) in both Purkinje and ventricular muscle fibers at a constant basic cycle length. In Purkinje fibers, the high concentration also slowed the kinetics of restitution of the action potential duration (tau c from 124.6 +/- 6.5 to 201.4 +/- 16.0 ms, p less than 0.01, n = 7), slowed the recovery kinetics of Vmax, and shifted the early portion of the normalized restitution curve toward longer action potential duration values in both fiber types. The range of premature action potential durations, defined as the difference between action potential durations during the first 100 ms of restitution, was decreased by the high concentration of propranolol in both Purkinje and ventricular muscle fibers by 39.5% and 33.9%, respectively. These findings indicate that (a) low concentrations of propranolol produced no direct electrophysiological effect, and (b) high concentrations of propranolol produced several potential antiarrhythmic effects in addition to the previously reported effects on Vmax and the action potential duration.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0160-2446
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
757-63
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Effects of propranolol on premature action potentials in canine Purkinje and ventricular muscle.
pubmed:affiliation
Krannert Institute of Cardiology, Department of Medicine, Indiana University College of Medicine, Indianapolis.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't