Inositol 1,4,5-trisphosphate receptors in the heart.
In: Poujeol, P and Petersen, O, (eds.)
PROCEEDINGS OF THE 3RD FEDERATION OF EUROPEAN PHYSIOLOGICAL SOCIETIES (FEPS).
(pp. 109 - 115).
MEDIMOND S R L
Inositol 1,4,5-trisphosphate (InsP(3)) is an established calcium-mobilising messenger, which is well-known to activate Ca2+ signalling in many cell types. Contractile cardiomyocytes express hormone receptors that are coupled to the production of InsP(3). Such cardioactive hormones, including endothelin, may have profound inotropic and arrhythmogenic actions, but it is unclear whether InsP(3) underlies any of these effects. We have examined the expression and localisation of InsP(3) receptors (InsP(3)Rs), and the potential role of InsP(3) in modulating excitation-contraction coupling (EC-coupling). Stimulation of electrically-paced atrial and ventricular myocytes with a membrane-permeant InsP(3) ester was found to evoke an increase in the amplitudes of action potential-evoked Ca2+ transients cause pro-arrhythmic diastolic Ca2+ transients. All the effects of the InsP(3) ester could be blocked using a membrane-permeant antagonist of InsP(3)Rs (2-aminoethoxydiphenyl borate; 2-APB). Our data indicate that atrial and ventricular cardiomyocytes express functional InsP(3)Rs, and these channels have the potential to influence EC-coupling.
|Title:||Inositol 1,4,5-trisphosphate receptors in the heart|
|Event:||3rd Congress of the Federation-of-European-Physiological-Societies|
|Dates:||2003-06-28 - 2003-07-02|
|Keywords:||RAT ATRIAL MYOCYTES, CALCIUM-RELEASE, CARDIAC MYOCYTES, FAILURE|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science|
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