title: Modeling calcium wave based on anomalous subdiffusion of calcium sparks in cardiac myocytes.
abstract: Ca(2+) sparks and Ca(2+) waves play important roles in calcium release and calcium propagation during the excitation-contraction (EC) coupling process in cardiac myocytes. Although the classical Fick's law is widely used to model Ca(2+) sparks and Ca(2+) waves in cardiac myocytes, it fails to reasonably explain the full-width at half maximum(FWHM) paradox. However, the anomalous subdiffusion model successfully reproduces Ca(2+) sparks of experimental results. In this paper, in the light of anomalous subdiffusion of Ca(2+) sparks, we develop a mathematical model of calcium wave in cardiac myocytes by using stochastic Ca(2+) release of Ca(2+) release units (CRUs). Our model successfully reproduces calcium waves with physiological parameters. The results reveal how Ca(2+) concentration waves propagate from an initial firing of one CRU at a corner or in the middle of considered region, answer how large in magnitude of an anomalous Ca(2+) spark can induce a Ca(2+) wave. With physiological Ca(2+) currents (2pA) through CRUs, it is shown that an initial firing of four adjacent CRUs can form a Ca(2+) wave. Furthermore, the phenomenon of calcium waves collision is also investigated.
authors.affiliation: State Key Laboratory of Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering, College of Engineering, Peking University, Beijing, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Jianhong
authors.initials: J
authors.lastname: Kang
authors.forename: Ceji
authors.initials: C
authors.lastname: Fu
authors.forename: Wenchang
authors.initials: W
authors.lastname: Tan
mesh_terms: D000818:Animals; D002021:Buffers; D020013:Calcium Signaling; D004396:Coloring Agents / Q000378:metabolism; D004058:Diffusion; D008954:Models, Biological; D032383:Myocytes, Cardiac / Q000378:metabolism*; D013997:Time Factors
chemical_list: D002021:Buffers; D004396:Coloring Agents