Adult Rat Left Ventricular Myocyte Model, 2001
Catherine
Lloyd
Bioengineering Institute, University of Auckland
Model Status
This CellML version of the model represents the epicardial cell. A number of inconsistencies in units and errors in equations from version 07 were fixed in this version. In addition to the formulation given by the paper and the author's later Corrections document, the IStim current has been adjusted to produce 1 Hz stimulations for 10 seconds.
Model Structure
Over the past decade electrophysiological studies have revealed transmural heterogeneity, or differences in the action potential waveforms recorded in cells isolated from the epicardial and the endocardial tissues in the left ventricles of mammalian hearts.
The adult rat has been widely used as an experimental model to investigate the electrical heterogeneity in the left ventricle under normal conditions and pathophysiological states. From this biophysical, experimental data, derived from patch clamp experiments, Sandeep V. Pandit, Robert B. Clark, Wayne R. Giles and Semahat S. Demir have developed a mathematical model of action potential heterogeneity in adult rat left ventricular myocytes (see the figure below). The mathematical models for the epicardial and endocardial cells of the rat left ventricle are based on the classical formulation of Hodgkin and Huxley (please see the CellML version of The Hodgkin-Huxley Squid Axon Model, 1952 for more details), and are therefore similar to previous computational work carried out by this research group (see Demir et al. Sinoatrial Node Model 1994 and Demir et al. Sinoatrial Node Model 1999). The endocardial cell model is based on the epicardial formulation with only slight modifications in certain parameters and equations.
The complete original paper reference is cited below:
A Mathematical Model of Action Potential Heterogeneity in Adult Rat Left Ventricular Myocytes, , Sandeep V. Pandit, Robert B. Clark, Wayne R. Giles and Semahat S. Demir, 2001,
Biophysical Journal
, 81, 3029-3051. (Full text and PDF versions of the article are available for Journal Members on the Biophysical Journal website.) PubMed ID: 11720973
fluid compartment model of the rat epicardial/endocardial ventricular cell
A fluid compartment model of the rat epicardial/endocardial ventricular cell.
Department of Physiology, Anatomy & Genetics, University of Oxford
unknown
Mike
Cooling
James
Lawson
Richard
2007-01-16T00:00:00+00:00
This model has been curated by Penny Noble of Oxford University
This version was created by Penny Noble of Oxford University and represents the EPICARDIAL CELL VARIANT. The model has been checked in COR.
Catherine
Lloyd
May
2008-06-13T13:56:13+12:00
Unknown Person
Added two differential equations to calculate HTRPNCa and LTRPNCa (the last two equations on page 3047 of the original paper). In doing so fixed the model to recreate the published results. Frank Sachse has checked this model in JSim and it also runs in this tool.
100000
0.001
2008-05-26T11:07:32+12:00
Noticed the volumes for V_NSR and V_SS were wrong and have corrected them. They were wrong in version 7.
R
Clark
B
Summary of code changes from v07:
1. The inward rectifying current (Ik1) had a 0.0001 term in the numerator which has been changed to 0.001 to match the paper and corrections document.
2. Mmax, hmax, jmax, dmax, f11max, f12max, Caactmax, rmax, smax sslowmax, rssmax and sssmax were all called minfinity, hinfinity, jinfinity, dinfinity...etc. These have been changed to ...max variables for consistency internally and with the paper.
3. The Ryanodine equations had odd dimensionless units and terms which divide by 1 to make the units work. Here variables 'n' and 'm' were removed and the units set as per the original model of Keizer, J. and Levine, L. Ryanodine receptor adaptation and Ca2+(-)induced Ca2+ release-dependent Ca2+ oscillations. Biophys. J. 71,6, 3477-3487 (1996). This was after discussion with both Catherine Lloyd and Penny Noble. The units are now correct.
4. Units millimolar_4 was misnamed and is now per_millimolar4.
5. Units nanoA_millimolar_4 was misnamed and is now nanoA_per_millimolar4.
6. Not a change but just to note that this implementation has a 1Hz stimulus for 10 seconds built in.
11720973
Several variables were given cmeta:id's to allow creation of a PCEnv session file.
2007-01-16T14:20:00+13:00
2007-06-22T14:17:56+12:00
11720973
2001-12-00 00:00
Biophysical Journal
Penny
Noble
J
A Mathematical Model of Action Potential Heterogeneity in Adult Rat Left Ventricular Myocytes
81
3029
3051
Biophysical Journal
S
Demir
S
2001-12-01 00:00
Oxford University
Department of Physiology, Anatomy & Genetics
R
Clark
B
Penny
Noble
J
S
Demir
S
Michael
Cooling
A mathematical model of action potential heterogeneity in adult rat left ventricular myocytes
81 6
3029
3051
penny.noble@dpag.ox.ac.uk
W
Giles
R
S
Pandit
V
2007-11-01T12:18:01+13:00
Michael
Cooling
W
Giles
R
S
Pandit
V
2008-05-26T11:07:32+12:00