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 chang e of binding and dissociation of Ca2+ ions to the regulatory protein t roponin C on the time course of isometric tension has been studied, us ing a mathematical model developed to investigate excitation-contracti on coupling in cardiac muscle cells. The numerical simulations show th at 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 experimen ts ill the view of the fact that no similar data have been reported fo r cardiac muscle cells as yet.