A model of the guinea-pig ventricular cardiac myocyte incorporating a transverse-axial tubular system
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | Progress in Biophysics and Molecular Biology |
| MU Faculty or unit | |
| Citation | |
| Field | Biophysics |
| Keywords | guinea pig; cardiac cell; transverse-axial tubular system; quantitative model |
| Description | A model of guinea-pig cardiac ventricular myocyte incorporating a transverse-axial tubular system (TATS) was developed. The model reproduces frequency-dependent changes of action potential shape and can replicate experimental data showing ion diffusion between the tubular lumen and external solution in guinea-pig myocytes.Theoretical analysis and model simulations show that, due to tight electrical coupling, tubular and surface membranes behave as a homogeneous whole during voltage and current clamp. However, during action potentials, restricted diffusion and ionic currents in TATS cause depletion of tubular Ca2+ and accumulation of tubular K+ (up to 19.8% and +3.4%, respectively, of bulk extracellular values, at 6 Hz). These changes, in turn, decrease ion fluxes across the TATS membrane and decrease sarcoplasmic reticulum (SR) Ca2+ load. Thus, the TATS plays a potentially important role in modulating the function of guinea-pig ventricular myocyte in physiological conditions. |
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