Journal article

The role of inositol 1,4,5-trisphosphate receptors in Ca2 signalling and the generation of arrhythmias in rat atrial myocytes

L Mackenzie, MD Bootman, M Laine, MJ Berridge, J Thuring, A Holmes, WH Li, P Lipp

JOURNAL OF PHYSIOLOGY-LONDON | CAMBRIDGE UNIV PRESS | Published : 2002

Abstract

Various cardio-active stimuli, including endothelin-1 (ET-1), exhibit potent arrhythmogenicity, but the underlying cellular mechanisms of their actions are largely unclear. We used isolated rat atrial myocytes and related changes in their subcellular Ca(2+) signalling to the ability of various stimuli to induce diastolic, premature extra Ca(2+) transients (ECTs). For this, we recorded global and spatially resolved Ca(2+) signals in indo-1- and fluo-4-loaded atrial myocytes during electrical pacing. ET-1 exhibited a higher arrhythmogenicity (arrhythmogenic index; ratio of number of ECTs over fold-increase in Ca(2+) response, 8.60; n = 8 cells) when compared with concentrations of cardiac glyc..

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University of Melbourne Researchers