Publication Date:
1980-08-08
Description:
Calcium ion-selective microelectrodes made with Simon's neutral carrier were used to measure simultaneously sarcoplasmic Ca2+ activity (aiCa) and resting tension (Tr) of rabbit ventricular muscle during reduction and restoration of external sodium ion concentration, [Na]0. Under the same experimental conditions the change in contractile tension (Ta) also measured. In resting muscle the aiCa was 38 +/- 17 nanomolar (mean +/- standard deviation; N = 10). The reduction of [Na]O from 153 to 20 millimolar led to about a threefold increase in aiCa with parallel increases in Tr and Ta. The time course of the change in aiCa was similar to that of the changes in Tr and Ta. The results are consistent with an important role of the sodium-calcium exchange system for regulating sarcoplasmic Ca2+ activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, C O -- Uhm, D Y -- Dresdner, K -- New York, N.Y. -- Science. 1980 Aug 8;209(4457):699-701.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7394527" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Biological Transport/drug effects
;
Calcium/*metabolism
;
Heart Ventricles/metabolism
;
Kinetics
;
Membrane Potentials/drug effects
;
Microelectrodes
;
Myocardium/*metabolism
;
Rabbits
;
Sarcoplasmic Reticulum/drug effects/*metabolism
;
Sodium/*metabolism/pharmacology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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