Document Detail

Role of changes in [Ca2+]i in energy deprivation contracture.
MedLine Citation:
PMID:  3664978     Owner:  NLM     Status:  MEDLINE    
Mechanisms of energy deprivation contracture were investigated in cultured chick embryo ventricular cells. In the presence of zero-extracellular-Na+, (choline chloride substitution)-nominal-zero-Ca2+ [( Ca2+] approximately 5 microM), exposure of ventricular cells to 1 mM cyanide (CN) and 20 mM 2-deoxyglucose (2-DG)-zero-glucose solution resulted in the development of a contracture (video motion detector) in 5.9 +/- 0.5 minutes. Early after contracture development, the resupply of extracellular Na+, in the continued presence of CN + 2-DG, resulted in a rapid partial relaxation (t1/2 = 1.9 +/- 0.3 seconds), associated with an increase in 45Ca efflux, presumably due to transsarcolemmal Ca2+ extrusion due to Na+-Ca2+ exchange. Resupply of glucose and removal of CN + 2-DG, in the continued absence of Na+, resulted in an initially slower (t1/2 = 11.6 +/- 2.5 seconds), but more complete relaxation of contracture, which was not associated with increased Ca2+ efflux. Pretreatment with 20 mM caffeine delayed the onset of contracture (9.2 +/- 1.1 minutes) and resulted in a contracture that could not be relaxed by resupply of external Na+ only. Studies using the fluorescent Ca2+ probe indo 1 demonstrated that in zero-Na+-zero-Ca2+ solutions, contracture due to CN + 2-DG was associated with an initial rise in [Ca2+]i but that this did not account for all of contracture force development. In cells exposed to CN + 2-DG in the presence of normal extracellular Na+ and Ca2+ concentrations, a small rise in [Ca2+]i was associated with initial contracture development, consistently preceding the development of a larger accelerated contracture presumably due to ATP depletion.(ABSTRACT TRUNCATED AT 250 WORDS)
W H Barry; G A Peeters; C A Rasmussen; M J Cunningham
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Circulation research     Volume:  61     ISSN:  0009-7330     ISO Abbreviation:  Circ. Res.     Publication Date:  1987 Nov 
Date Detail:
Created Date:  1987-12-11     Completed Date:  1987-12-11     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0047103     Medline TA:  Circ Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  726-34     Citation Subset:  IM    
Department of Medicine, University of Utah, School of Medicine, Salt Lake City.
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MeSH Terms
Adenosine Triphosphate / physiology
Caffeine / pharmacology
Calcium / physiology*
Cells, Cultured
Chick Embryo
Cyanides / pharmacology
Deoxyglucose / pharmacology
Energy Metabolism*
Fluorescent Dyes
Myocardial Contraction* / drug effects
Sodium / pharmacology
Grant Support
Reg. No./Substance:
0/Cyanides; 0/Fluorescent Dyes; 0/Indoles; 154-17-6/Deoxyglucose; 56-65-5/Adenosine Triphosphate; 58-08-2/Caffeine; 7440-23-5/Sodium; 7440-70-2/Calcium; 96314-96-4/indo-1

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