Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
|
pubmed:dateCreated |
1991-4-18
|
pubmed:abstractText |
We investigated the net transsarcolemmal Ca2+ shifts and Ca/Ca exchange by means of 45Ca in isolated, perfused ventricles of guinea pig heart treated with vanadate to inhibit ATP-driven sarcolemmal Ca2+ pump. The heart was stimulated (at the rate of 60/min) and perfused with a solution containing 45Ca for 60 min. Thereafter stimulation was stopped and either perfusion with radioactive solution was continued or the solution was exchanged for a non-radioactive one. In the first case, tissue 45Ca content (equivalent to the exchangeable Ca2+ content) dropped from 1.960 +/- 0.120 mmol/kg of wet weight (w.w.) to 0.715 +/- 0.049 mmol/kg w.w. and stabilized at this level between 5th and 10th min. In the second case, decrease in 45Ca content continued and within 40 min attained 0.047 +/- 0.004 mmol/kg w.w., despite stabilizing of the total exchangeable Ca2+ content. Drop of 45Ca content in the rested heart perfused (until the end of experiments) with radioactive solution resulted from the net transsarcolemmal Ca2+ shift and it was strongly inhibited by removal of extracellular Na+. The continuing drop in 45Ca content in the heart perfused with non-radioactive solution while total Ca2+ content stabilized must have resulted from Ca/Ca exchange; it was stimulated by removal of extracellular Na+. These experiments separate two modes of 45Ca fluxes and suggest that a common route of these fluxes is the Na/Ca exchanger.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:issn |
0300-8428
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
85
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
585-94
|
pubmed:dateRevised |
2006-11-15
|
pubmed:meshHeading |
pubmed-meshheading:2076094-Animals,
pubmed-meshheading:2076094-Calcium,
pubmed-meshheading:2076094-Guinea Pigs,
pubmed-meshheading:2076094-Heart Ventricles,
pubmed-meshheading:2076094-Homeostasis,
pubmed-meshheading:2076094-Ion Exchange,
pubmed-meshheading:2076094-Kinetics,
pubmed-meshheading:2076094-Myocardium,
pubmed-meshheading:2076094-Sarcolemma,
pubmed-meshheading:2076094-Sodium
|
pubmed:articleTitle |
Net transsarcolemmal Ca2+ shifts versus Ca/Ca exchange in guinea pig ventricular muscle.
|
pubmed:affiliation |
Department of Clinical Physiology, Medical Center of Postgraduate Education, Warsaw, Poland.
|
pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|