# Model of Excitation-Contraction in a uterine SMC

### About this model

Original publication: | |
---|---|

Bursztyn, Limor, et al (2007): "Mathematical model of excitation-contraction in a uterine smooth muscle cell." American Journal of Physiology-Cell Physiology 292.5 (2007): C1816-C1829. | |

DOI: | https://pubmed.ncbi.nlm.nih.gov/17267547/ |

### Model status

The current CellML implementation runs in OpenCOR.
The results have been validated against the data extracted from the figures in the published Bursztyn, Limor, et al (2007). We found a few inconsistencies in parameter values and units presented in the primary paper. While the primary paper does not provide complete simulation experiment settings, we provide the settings used for the figure reproduction with the simulation results shown under `Experiments`. The model structure can be found in the documentation of `Components`. The limitation and curation process has been summarized in the Model history and Known issues.

### Model overview

This workspace holds a CellML encoding of the Bursztyn, Limor, et al (2007) model.
The Bursztyn, Limor, et al (2007) paper describes three *Ca*^{2 + } control mechanisms: voltage-operated *Ca*^{2 + } channels, *Ca*^{2 + } pumps and *Na*^{ + } ⁄ *Ca*^{2 + } exchangers, which employ the mathematical formulation proposed in Parthimos, Dimitris et al (1999). The cross-bridge model of Hai and Murphy (1988) is used to describe the processes of myosin light chain (MLC) phosphorylation and stress production, which is essentially a deterministic multi-state Markov model (MM).

### Modular description

#### Components

CellML divides the mathematical model into distinct components, which are able to be re-used. The main CellML components are:

- Ions fluxes component, including:
- L-type voltage dependent
*Ca*^{2 + }channels*J*_{VOCC}, and the computation of current reuses the imported ionic current components - the efflux through
*Ca*^{2 + }pump*J*_{Ca, pump} - the flux through the
*Na*^{ + }⁄*Ca*^{2 + }exchangers*J*_{Na ⁄ Ca}

- L-type voltage dependent

Excitation-contraction unit, which decouples the connection between the excitation and contraction. This is used to test individual ion fluxes and contraction development.

Each of these blocks is itself a CellML model, which enables us to reuse the various components in future studies and models.

#### Experiments

Following best practices, this model separates the mathematics from the parameterisation of the model. The mathematical model is imported into a specific parameterised instance in order to perform numerical simulations. The parameterisation would include defining the stimulus protocol to be applied.

This workspace has seven sets of experiments and corresponding simulation results:

#### Simulation settings

Simulation settings are encoded in SED-ML documents for experiment execution. It is common that we may need to vary experimental settings to obtain data under various conditions. Hence, the full experimental settings are encoded in the simulation scripts.
The Python scripts to run simulation and reproduce the figures in the original paper are included under the `Simulation` folder.

### Model history

There is no publicly available code for this model.

### Known issues

- A few inconsistencies of parameter values and units, which seems to be typos and listed in the following table.

- The specification of experiment settings for simulation is incomplete in the primary paper, and the experiment settings that we use are summarized along with simulation results.