Inositol 1,4,5-Trisphosphate Receptors (InsP3R): "Exciting" Players in Cardiac Excitation-Contraction Coupling?
Ca2+ release through ryanodine receptor (RyR) intracellular Ca2+ release channels plays the leading role in regulation of myocyte contraction. However, Ca2+ signals arising from their less abundant inositol 1,4,5-trisphosphate sensitive counterparts (InsP3R), also localised to intracellular stores, is emerging as an important modulator of Ca2+-sensitive processes in cardiac myocytes. In this month's issue of Circulation, Rota et al1 report that activation of InsP3R Ca2+ release channels by G-protein coupled receptor (GPCR) signalling regulates the electrical properties of human myocardium. Their results provide new insights into how InsP3 induced Ca2+ release (IICR) modulates cardiomyocyte Ca2+ handling and contractility through influencing sarcolemmal membrane potential and ionic currents.
- Received August 14, 2013.
- Accepted August 16, 2013.