Document Detail


Electrical restitution process in dispersed canine cardiac Purkinje and ventricular cells.
MedLine Citation:
PMID:  3688246     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Rate-dependent changes in cardiac action potential duration (APD) have been related to ion accumulation and depletion in restricted extracellular spaces. Isolated cardiac cells lack intercellular clefts and thus are less likely than intact tissue to experience ionic transients immediately outside the plasma membrane. Furthermore, isolated Purkinje cells lack the T tubules found in ventricular tissue and cells, which also can be a site of ion accumulation and depletion. We therefore employed single canine ventricular and Purkinje cells to investigate the contribution of restricted spaces to the electrical restitution process. In both cell types, abrupt changes in cycle length do not alter resting potential, but APD alters with a time constant of approximately 1 min. In addition, both preparations exhibit two components to the electrical restitution process of the APD. The rapid component has a time constant of 66 +/- 17 ms in the ventricle cells and 186 +/- 43 ms in the Purkinje cells. The slower component is both smaller and more variable. These values are similar to those reported in intact canine ventricular and Purkinje tissue. Thus the restitution process of APD, as measured in these isolated cardiac cells, is not markedly dependent on the presence or absence of restricted extracellular spaces.
Authors:
R B Robinson; P A Boyden; B F Hoffman; K W Hewett
Related Documents :
10635016 - Transcriptional regulation of the pou gene oct-6 in schwann cells.
9648886 - Ceramide and its interconvertible metabolite sphingosine function as indispensable lipi...
8146156 - Schwann cells transplanted in the lateral ventricles prevent the functional and anatomi...
19179536 - Calcineurin/nfat signaling is required for neuregulin-regulated schwann cell differenti...
1846486 - Herpes simplex virus (hsv) glycoprotein h is partially processed in a cell line that ex...
2353416 - Ultrastructural morphogenesis of 4-ipomeanol-induced bronchiolitis and interstitial pne...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  253     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1987 Nov 
Date Detail:
Created Date:  1988-01-12     Completed Date:  1988-01-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H1018-25     Citation Subset:  IM    
Affiliation:
Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Action Potentials
Animals
Dogs
Electrophysiology
Heart Ventricles / cytology
Myocardium / cytology*
Purkinje Cells / physiology*
Tetrodotoxin / pharmacology
Grant Support
ID/Acronym/Agency:
P01-HL-30557/HL/NHLBI NIH HHS; R01-HL-34477/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
4368-28-9/Tetrodotoxin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Lesions of A1 noradrenergic cells affect AVP release and heart rate during hemorrhage.
Next Document:  Sarcolemmal Na+-Ca2+ exchange activity in hearts subjected to hypoxia reoxygenation.