Calcium Sparks in Cardiac Pacemaker Cells at Different Temperatures in silico

Temperature effects play an important role in the functioning of the cardiac cell. In this work we simulated the influence of temperature on calcium dynamics properties such as spontaneous calcium release frequency and amplitude while taking into account the experimental data on the response of various protein complexes to the temperature shift. We investigated temperature effects of protein complexes involved in calcium dynamics: calsequestrin and sarco-endoplasmic reticulum ATPase. The contribution of each of them to the temperature effect was explored. Furthermore, we introduced a novel approach of modelling the ryanodine receptors (RyRs) temperature effects and the contribution of RyRs thermal fluctuations to the whole cell temperature dependence was evaluated. The main result of our research is a generalization of the facts of the temperature influence on various calcium cycling proteins in the cardiac cell. Our main assumption is that calsequestrin makes the main contribution to the increase of calcium release frequency and in the increase of calcium concentration in sarcoplasmic reticulum.