Computer simulation of excitation-contraction coupling in cardiac muscle. A study of the regulatory role of calcium binding to troponin C.

The influence of a change of troponin concentration as well of a change of binding and dissociation of Ca2+ ions to the regulatory protein troponin C on the time course of isometric tension has been studied, using a mathematical model developed to investigate excitation-contraction coupling in cardiac muscle cells. The numerical simulations show that peak amplitude, rate of force development, time to peak tension and relaxation time depend significantly on the above parameters even in the case when the equilibrium dissociation constant remains unchanged. The obtained results might be useful for the planing of new experiments in the view of the fact that no similar data have been reported for cardiac muscle cells as yet.