Ion Flux in Cardiac Models

with Saleh Amirriazi, Stephany Chang and Anushka Michailova, University of California, San Diego

This experiment concerns a mathematical model of excitation-contraction coupling in the rabbit ventricular myocytes. In the Shannon model a system of ordinary differential equations is used to describe the intracellular ionic fluxes (for Ca²⁺ and Na⁺). The model incorporates many features of cell structure and is able to reproduce experimental data using parameters based on measurements in rabbit cells. An extended model incorporates Mg²⁺-nucleotide regulation. The experiment involves validation of the updated model by varying nine input parameters so that the predicted currents are as close as possible to the experimentally measured. This was phrased as a optimization problem using Nimrod/O, minimizing the differences between computed metabolic factors and experimental values.

Results were presented at Biophysics 2008, Long Beach, California, February 2008.