Přístupnostní navigace
E-application
Search Search Close
Publication detail
PÁSEK, M. ŠIMURDA, J. ORCHARD, C. CHRISTÉ, G.
Original Title
A model of the guinea-pig ventricular cardiac myocyte incorporating a transverse-axial tubular system
Type
journal article - other
Language
English
Original Abstract
A model of the guinea-pig cardiac ventricular myocyte has been developed that includes a representation of the transverse-axial tubular system (TATS), including heterogeneous distribution of ion flux pathways between the surface and tubular membranes. The model reproduces frequency-dependent changes of action potential shape and intracellular ion concentrations and can replicate experimental data showing ion diffusion between the tubular lumen and external solution in guinea-pig myocytes. The model is stable at rest and during activity and returns to rested state after perturbation. 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 (maximum difference 0.9 mV at peak tubular INa of -38 nA). 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 SR Ca2+ load. Thus, the TATS plays a potentially important role in modulating the function of guinea-pig ventricular myocyte in physiological conditions.
Keywords
ion accumulation, ion depletion; extracellular space; TATS; restricted diffusion; quantitative model
Authors
PÁSEK, M.; ŠIMURDA, J.; ORCHARD, C.; CHRISTÉ, G.
RIV year
2008
Released
30. 11. 2007
Publisher
ISSN 0079-6107
Location
Great Britain
ISBN
0079-6107
Periodical
PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY
Year of study
2007 (96)
Number
1-3
State
United Kingdom of Great Britain and Northern Ireland
Pages from
258
Pages to
280
Pages count
23
BibTex
@article{BUT45341, author="Michal {Pásek} and Jiří {Šimurda}", title="A model of the guinea-pig ventricular cardiac myocyte incorporating a transverse-axial tubular system", journal="PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY", year="2007", volume="2007 (96)", number="1-3", pages="258--280", issn="0079-6107" }