Document Detail


Inactivation of L-type calcium channels in cardiomyocytes. Experimental and theoretical approaches.
MedLine Citation:
PMID:  15113117     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The L-type calcium current (ICa) plays an important role in excitation-contraction coupling of heart cells. It is critical for forming the major trigger for Ca(2+)-induced Ca(2+) release from the sarcoplasmic reticulum and hence its feedback regulation is of fundamental biological significance. The channel inactivation sharpens the kinetics and temporal precision of the Ca(2+) signals so that it prevents longer-term increases in free intracellular Ca(2+) concentration. Cardiac L-type Ca(2+) channels are known to inactivate through voltage- and Ca(2+)-dependent mechanisms. Pure voltage-dependent inactivation has a much slower time course of development than Ca(2+)-dependent inactivation and plays minor role in inhibition of Ca(2+) influx into the cell. The major determinant of the inactivation kinetics of Ca(2+) current during depolarization is Ca(2+)-dependent mechanisms. Furthermore, it is possible to distinguish two phases in Ca(2+)-dependent inactivation of calcium current: a slow phase that depends on Ca(2+) flow through the channels (Ca(2+) current-dependent inactivation) and a fast one that depends on Ca(2+) released from the sarcoplasmic reticulum (Ca(2+) release-dependent inactivation). Although both Ca(2+) released from the SR and Ca(2+) permeating channels play a role, SR-released Ca(2+) is the most effective inactivation mechanism in inhibition of Ca(2+) entry through the channel.
Authors:
Z Kubalová
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Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  General physiology and biophysics     Volume:  22     ISSN:  0231-5882     ISO Abbreviation:  Gen. Physiol. Biophys.     Publication Date:  2003 Dec 
Date Detail:
Created Date:  2004-04-28     Completed Date:  2004-08-24     Revised Date:  2005-11-16    
Medline Journal Info:
Nlm Unique ID:  8400604     Medline TA:  Gen Physiol Biophys     Country:  Slovakia    
Other Details:
Languages:  eng     Pagination:  441-54     Citation Subset:  IM    
Affiliation:
Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia. umfgkuba@savba.sk
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MeSH Terms
Descriptor/Qualifier:
Animals
Calcium / metabolism*
Calcium Channels, L-Type / physiology*
Humans
Ion Channel Gating / physiology*
Membrane Potentials / physiology
Models, Cardiovascular*
Myocardial Contraction / physiology*
Myocytes, Cardiac / physiology*
Sarcoplasmic Reticulum / physiology*
Chemical
Reg. No./Substance:
0/Calcium Channels, L-Type; 7440-70-2/Calcium

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


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