Linked Life Data

1713486

Source:http://linkedlifedata.com/resource/pubmed/id/1713486

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1991-8-30
pubmed:abstractText
Guinea-pig cardiac myocytes loaded intracellularly with Na+ show spontaneous contractile activity and transient membrane depolarizations or inward currents. We have investigated whether both phenomena can be attributed to release of Ca2+ from overloaded cellular stores causing contractile activation and at the same time generating an inward current due to Ca2+ efflux by the electrogenic Na+/Ca2+ exchange. Variations in membrane potential by voltage clamp or in ionic composition of the superfusion medium changed the amplitude and frequency of spontaneous inward currents in the direction expected from computations of the Na+/Ca2+ exchange. Caffeine in concentrations that activate the Ca2+ release channel of the sarcoplasmic reticulum produced a vigorous contraction accompanied by a large current transient. After exposure to ryanodine both Isp and spontaneous contractions were abolished. Spontaneous inward currents were depressed by inhibitors of the Na+/Ca2+ exchange. The results with caffeine and ryanodine demonstrate that unimpaired sarcoplasmic reticular function is a prerequisite for both the contractile and the electrical event. From the characteristics of Isp it is proposed that this current is due to electrogenic Na+/Ca2+ exchange.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0778-3124
pubmed:author
pubmed:issnType
Print
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
49-59
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Spontaneous activity of sodium loaded guinea-pig cardiac myocytes: contribution of Na+/Ca2+ exchange.
pubmed:affiliation
Institut für Pharmakologie, Medizinische Einrichtungen der Universität--Gesamthochschule Essen, West Germany.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't