Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-6-27
pubmed:abstractText
Propranolol, timolol and sotalol were compared with respect to their cardiotoxic properties in isolated, spontaneously beating rat hearts. Propranolol and timolol induced a dose-dependent decrease in myocardial contractility. A high dose of sotalol had only modest negative inotropic effects. Similar reductions in myocardial contractility were observed in isolated, ventricle-stimulated rat hearts. These observations were similar to those in a previous study in which spontaneously beating and ventricle-stimulated reserpinized rat hearts were investigated. Spontaneously beating rat hearts were perfused with a high-, a normal- and a low-Ca++ medium, each with and without propranolol, timolol and sotalol. Addition of each beta-blocker to a normal-Ca++ medium induced a decrease of myocardial contractility and of heart rate and an increase of AV-conduction time when compared with the drug-free medium. In a high-Ca++ medium containing the same concentration of each beta-blocker, a less pronounced decrease of myocardial contractility was observed. Heart rate decreased and AV-conduction time increased to the same extent as after perfusion with the drug containing normal-Ca++ medium. With respect to the corresponding drug-free medium perfusion with a low-Ca++ medium with each beta-blocker enhanced the decline in myocardial contractility, most pronounced in propranolol and timolol containing media. For propranolol and sotalol the decrease in heart rate and increase in AV-conduction time were similar to the results after administration of the same beta-blocker in a high- and a normal-Ca++ perfusion media. Timolol caused an electromechanical dissociation. It was concluded that in beta-blocker intoxication the negative-inotropic phenomena cannot be explained by an action of the drugs on the beta-receptor since the results in reserpinized and non-reserpinized rat hearts were similar. Other effects have to be responsible for the observed cardiotoxic phenomena. The present results indicate that these phenomena can be influenced by Ca++ and or can be attributed to differences in lipophilicity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0731-3810
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
111-33
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Calcium interferes with the cardiodepressive effects of beta-blocker overdose in isolated rat hearts.
pubmed:publicationType
Journal Article, In Vitro