A mathematical treatment of integrated Ca dynamics within the ventricular myocyte
Martin
Fink
Oxford University
Model Status
This model runs in PCEnv, OpenCell and COR to recreate the published results. The units are consistent throughout. The model equations and output were checked using the original matlab code, and it currently recreates the Pace1 Stimulus protocol described.
Model Structure
ABSTRACT: We have developed a detailed mathematical model for Ca2+ handling and ionic currents in the rabbit ventricular myocyte. The objective was to develop a model that: 1), accurately reflects Ca-dependent Ca release; 2), uses realistic parameters, particularly those that concern Ca transport from the cytosol; 3), comes to steady state; 4), simulates basic excitation-contraction coupling phenomena; and 5), runs on a normal desktop computer. The model includes the following novel features: 1), the addition of a subsarcolemmal compartment to the other two commonly formulated cytosolic compartments (junctional and bulk) because ion channels in the membrane sense ion concentrations that differ from bulk; 2), the use of realistic cytosolic Ca buffering parameters; 3), a reversible sarcoplasmic reticulum (SR) Ca pump; 4), a scheme for Na-Ca exchange transport that is [Na]i dependent and allosterically regulated by [Ca]i; and 5), a practical model of SR Ca release including both inactivation/adaptation and SR Ca load dependence. The data describe normal electrical activity and Ca handling characteristics of the cardiac myocyte and the SR Ca load dependence of these processes. The model includes a realistic balance of Ca removal mechanisms (e.g., SR Ca pump versus Na-Ca exchange), and the phenomena of rest decay and frequency-dependent inotropy. A particular emphasis is placed upon reproducing the nonlinear dependence of gain and fractional SR Ca release upon SR Ca load. We conclude that this model is more robust than many previously existing models and reproduces many experimental results using parameters based largely on experimental measurements in myocytes.
The complete original paper reference is cited below:
A mathematical treatment of integrated Ca dynamics within the ventricular myocyte, Thomas R. Shannon, Fei Wang, Jose Puglisi, Christopher Weber and Donald M. Bers, 2004, Biophysical Journal, 87, 3351-3371. PubMed ID: 15347581
cell diagram
A schematic diagram of the cell model which highlights the calcium- and sodium-dependent components of the model in particular.
units checked, curated
keyword
calcium dynamics
cardiac
electrophysiology
2007-12-03T07:29:30+13:00
Penny
Noble
Christopher
Weber
This CellML model was created by Martin Fink of Oxford University using COR. In collaboration with the authors of the published model this CellML model has been modified such that it contains no typographical errors and is able to run in PCEnv and COR to produce an action potential. The units in this model have also been checked and curated.
2008-02-25T12:16:44+13:00
10000
10000
Fixed all warnings in COR.
A Mathematical Treatment of Integrated Ca Dynamics within the
Ventricular Myocyte
87
3351
3371
Thomas
Shannon
R
This is the CellML description of Shannon et al.'s 2004 mathematical model of integrated calcium dynamics within the ventricular myocyte.
Jose
Puglisi
Penny
Noble
J
Fei
Wang
2004-11-00 00:00
2007-12-03T00:00:00+00:00
Donald
Bers
M
Martin
Fink
Oxford University
Biophysical Journal
James Lawson
Modified version of the model which runs to recreate the published results.
15347581
Catherine Lloyd