Calcium in Heart Function and Diseases
Ca2+ signaling refers to coupling of membrane excitation to contractile activation of heart muscle. Mechanisms permitting cyclic rise and reduction of Ca2+ concentration within cardiac muscle cells are required for optimal heart beating. Alterations of these mechanisms are followed by deficient contraction and relaxation.
Ca2+ signaling serves as a common mechanism to couple membrane excitation to intracellular functions in most biological tissues (Clapham 2007). This mechanism is based on: (a) a high gradient between extracellular (or intracellular stores) Ca2+ concentration (mM) and intracellular (cytosolic) Ca2+ concentration (0.1 μM); (b) passive fluxes of signaling Ca2+through selective channels from extracellular fluids (or intracellular stores) into the cytosol; (c) the presence of intracellular proteins, such as calmodulin and troponin,...
The author is partially supported by NHLBI Grant RO1-69830