Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
|
pubmed:dateCreated |
1993-8-20
|
pubmed:abstractText |
During acute myocardial ischemia, a combination of increased extracellular K+ concentration and sympathetic nerve activation exists. Using a perfused innervated rat heart model, we studied the influence of increased extracellular K+ concentrations on neural norepinephrine (NE) release, adrenergic stimulation-induced K+ uptake by the heart, and the occurrence of ventricular arrhythmias. Hearts were globally perfused with control (4 mM) or increased concentrations of K+ (7-16 mM). Sympathetic nerve stimulation-induced NE release was analyzed by radioenzymatic assay. Cardiac K+ uptake was assessed by the reduction in K+ concentration in the coronary venous effluent induced by nerve stimulation. Neural NE release was not influenced by increasing K+ from 4 mM to 7, 10, and 13 mM, but was suppressed by 16 mM K+ (-40 +/- 10%). Nerve stimulation induced cardiac uptake of K+, which was blocked by the beta-adrenoceptor antagonist timolol. This stimulated K+ uptake was substantially enhanced by increasing extracellular K+ and was also dependent on the intensity of sympathetic stimulation at 10 mM K+. Sympathetic nerve stimulation, together with a high K+ of 10 mM, was potent in initiating ventricular tachyarrhythmias, and quantitative NE release was well correlated with the frequency of ventricular arrhythmias. Our results demonstrate the synergistic effects of increased extracellular K+ and sympathetic activation, which may be involved in the genesis of ventricular arrhythmias.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
Jun
|
pubmed:issn |
0160-2446
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
21
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
977-82
|
pubmed:dateRevised |
2007-11-15
|
pubmed:meshHeading |
pubmed-meshheading:7687726-Animals,
pubmed-meshheading:7687726-Arrhythmias, Cardiac,
pubmed-meshheading:7687726-Electric Stimulation,
pubmed-meshheading:7687726-Extracellular Space,
pubmed-meshheading:7687726-Heart,
pubmed-meshheading:7687726-Male,
pubmed-meshheading:7687726-Myocardium,
pubmed-meshheading:7687726-Neurons,
pubmed-meshheading:7687726-Norepinephrine,
pubmed-meshheading:7687726-Potassium,
pubmed-meshheading:7687726-Rats,
pubmed-meshheading:7687726-Rats, Sprague-Dawley,
pubmed-meshheading:7687726-Sympathetic Nervous System
|
pubmed:year |
1993
|
pubmed:articleTitle |
Sympathetic activation and increased extracellular potassium: synergistic effects on cardiac potassium uptake and arrhythmias.
|
pubmed:affiliation |
Department of Medicine (RIE), University of Edinburgh, Scotland.
|
pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
|