Adult Rat Left Ventricular Myocyte Model, 2001
Catherine
Lloyd
Bioengineering Institute, University of Auckland
Model Status
This CellML version of the model represents the endocardial cell. The model has been checked in COR, OpenCell and JSim and it runs in all three to recreate the published results. The units have been checked and are consistent. Thank you to Frank Sachse for his helpful feedback and careful code checking.
Model Structure
ABSTRACT: Mathematical models were developed to reconstruct the action potentials (AP) recorded in epicardial and endocardial myocytes isolated from the adult rat left ventricle. The main goal was to obtain additional insight into the ionic mechanisms responsible for the transmural AP heterogeneity. The simulation results support the hypothesis that the smaller density and the slower reactivation kinetics of the Ca(2+)-independent transient outward K(+) current (I(t)) in the endocardial myocytes can account for the longer action potential duration (APD), and more prominent rate dependence in that cell type. The larger density of the Na(+) current (I(Na)) in the endocardial myocytes results in a faster upstroke (dV/dt(max)). This, in addition to the smaller magnitude of I(t), is responsible for the larger peak overshoot of the simulated endocardial AP. The prolonged APD in the endocardial cell also leads to an enhanced amplitude of the sustained K(+) current (I(ss)), and a larger influx of Ca(2+) ions via the L-type Ca(2+) current (I(CaL)). The latter results in an increased sarcoplasmic reticulum (SR) load, which is mainly responsible for the higher peak systolic value of the Ca(2+) transient [Ca(2+)](i), and the resultant increase in the Na(+)-Ca(2+) exchanger (I(NaCa)) activity, associated with the simulated endocardial AP. In combination, these calculations provide novel, quantitative insights into the repolarization process and its naturally occurring transmural variations in the rat left ventricle.
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. PubMed ID: 11720973
fluid compartment model of the rat epicardial/endocardial ventricular cell
A fluid compartment model of the rat epicardial/endocardial ventricular cell.
Rat ventricular myocyte model from the original Pandit 2001 paper: endocardial cell
Department of Physiology, Anatomy & Genetics, University of Oxford
S
Demir
S
James
Lawson
Richard
R
Clark
B
11720973
This model has been curated by Penny Noble of Oxford University
S
Pandit
V
Catherine
Lloyd
May
This file contains a CellML description of Pandit et al.'s 2001 model of action potential heterogeneity in adult rat left ventricular myocytes. This variant describes the ENDOCARDIAL cell.
penny.noble@dpag.ox.ac.uk
100000
0.001
2006-01-01
2007-06-22T14:17:56+12:00
Several variables were given cmeta:id's to allow creation of a PCEnv session file.
2007-01-16T14:20:00+13:00
Catherine Lloyd
2001-12-01 00:00
keyword
electrophysiology
ventricular myocyte
cardiac
rat
2007-01-16T00:00:00+00:00
unknown
Penny
Noble
J
Biophysical Journal
This version was created by Penny Noble of Oxford University and represents the EPICARDIAL CELL VARIANT. The model has been checked in COR, PCEnv and JSim and it runs in all three to recreate the published results. The units have been checked and are consistent. Thank you to Frank Sachse for his helpful feedback and careful code checking.
A mathematical model of action potential heterogeneity in adult rat left ventricular myocytes
81 6
3029
3051
Penny
Noble
J
Oxford University
Department of Physiology, Anatomy & Genetics
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.
W
Giles
R
James Lawson
2007-11-01T12:18:01+13:00