Lb. Katsnelson et Vs. Markhasin, MATHEMATICAL-MODELING OF RELATIONS BETWEEN THE KINETICS OF FREE INTRACELLULAR CALCIUM AND MECHANICAL FUNCTION OF MYOCARDIUM, Journal of Molecular and Cellular Cardiology, 28(3), 1996, pp. 475-486
The paper describes a mathematical model of cardiac muscle contraction
based on the assumption of two types of co-operativity which control
the formation of calcium-troponin complexes and on a simplified scheme
of free intracellular calcium kinetics. Calcium transients are shown
to be different in isotonic and isometric conditions, being dependent
on initial muscle length as well. Numerical experiments and analysis o
f the model suggest that calcium uptake by the sarcoplasmic reticulum
slows down with an increase in the intracellular concentration of free
calcium. This suggestion enables the model to explain the disappearan
ce of load-dependent relaxation observed experimentally at cardiac hyp
ertrophy. (C) 1996 Academic Press Limited