Calcium waves initiating from the anomalous subdiffusive calcium sparks

Abstract

The objective of the study is to investigate the propagation of Ca 2+ waves in full-width cardiac myocytes and carry out sensitivity analysis to study the effects of various physiological parameters on global Ca 2+ waves. Based on the anomalous subdiffusion of Ca 2+ sparks, a mathematical model was proposed to characterize the Ca 2+ waves. The computed results were in agreement with the experimental measurements using confocal microscopy. This model includes variables of current through the Ca 2+ release unit (CRU; I CRU ), duration of current flow through CRU ( T open ), Ca 2+ sensitivity parameter ( K ), the longitudinal and transverse spatial separation of CRUs ( l x and l y , where x denotes longitudinal direction ( x -axis) and y denotes transverse direction ( y -axis)) and Ca 2+ diffusion coefficients ( D x , D y ). The spatio-temporal mechanism of the anomalous Ca 2+ sparks led to results that were different from those based on Fick's law. The major findings were reported as: I CRU affected the dynamic properties of Ca 2+ waves more significantly than T open ; the effect of K on the properties of Ca 2+ waves was negligible; l y affected the amplitude significantly, but l x affected the longitudinal velocity significantly; in turn, the limitation and significance of the study are discussed.