Cargando…
An integrated finite element simulation of cardiomyocyte function based on triphasic theory
In numerical simulations of cardiac excitation-contraction coupling, the intracellular potential distribution and mobility of cytosol and ions have been mostly ignored. Although the intracellular potential gradient is small, during depolarization it can be a significant driving force for ion movemen...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2015
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4611143/ https://www.ncbi.nlm.nih.gov/pubmed/26539124 http://dx.doi.org/10.3389/fphys.2015.00287 |
_version_ | 1782396061992615936 |
---|---|
author | Hatano, Asuka Okada, Jun-Ichi Washio, Takumi Hisada, Toshiaki Sugiura, Seiryo |
author_facet | Hatano, Asuka Okada, Jun-Ichi Washio, Takumi Hisada, Toshiaki Sugiura, Seiryo |
author_sort | Hatano, Asuka |
collection | PubMed |
description | In numerical simulations of cardiac excitation-contraction coupling, the intracellular potential distribution and mobility of cytosol and ions have been mostly ignored. Although the intracellular potential gradient is small, during depolarization it can be a significant driving force for ion movement, and is comparable to diffusion in terms of net flux. Furthermore, fluid in the t-tubules is thought to advect ions to facilitate their exchange with the extracellular space. We extend our previous finite element model that was based on triphasic theory to examine the significance of these factors in cardiac physiology. Triphasic theory allows us to study the behavior of solids (proteins), fluids (cytosol) and ions governed by mechanics and electrochemistry in detailed subcellular structures, including myofibrils, mitochondria, the sarcoplasmic reticulum, membranes, and t-tubules. Our simulation results predicted an electrical potential gradient inside the t-tubules at the onset of depolarization, which corresponded to the Na(+) channel distribution therein. Ejection and suction of fluid between the t-tubules and the extracellular compartment during isometric contraction were observed. We also examined the influence of t-tubule morphology and mitochondrial location on the electrophysiology and mechanics of the cardiomyocyte. Our results confirm that the t-tubule structure is important for synchrony of Ca(2+) release, and suggest that mitochondria in the sub-sarcolemmal region might serve to cancel Ca(2+) inflow through surface sarcolemma, thereby maintaining the intracellular Ca(2+) environment in equilibrium. |
format | Online Article Text |
id | pubmed-4611143 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-46111432015-11-04 An integrated finite element simulation of cardiomyocyte function based on triphasic theory Hatano, Asuka Okada, Jun-Ichi Washio, Takumi Hisada, Toshiaki Sugiura, Seiryo Front Physiol Physics In numerical simulations of cardiac excitation-contraction coupling, the intracellular potential distribution and mobility of cytosol and ions have been mostly ignored. Although the intracellular potential gradient is small, during depolarization it can be a significant driving force for ion movement, and is comparable to diffusion in terms of net flux. Furthermore, fluid in the t-tubules is thought to advect ions to facilitate their exchange with the extracellular space. We extend our previous finite element model that was based on triphasic theory to examine the significance of these factors in cardiac physiology. Triphasic theory allows us to study the behavior of solids (proteins), fluids (cytosol) and ions governed by mechanics and electrochemistry in detailed subcellular structures, including myofibrils, mitochondria, the sarcoplasmic reticulum, membranes, and t-tubules. Our simulation results predicted an electrical potential gradient inside the t-tubules at the onset of depolarization, which corresponded to the Na(+) channel distribution therein. Ejection and suction of fluid between the t-tubules and the extracellular compartment during isometric contraction were observed. We also examined the influence of t-tubule morphology and mitochondrial location on the electrophysiology and mechanics of the cardiomyocyte. Our results confirm that the t-tubule structure is important for synchrony of Ca(2+) release, and suggest that mitochondria in the sub-sarcolemmal region might serve to cancel Ca(2+) inflow through surface sarcolemma, thereby maintaining the intracellular Ca(2+) environment in equilibrium. Frontiers Media S.A. 2015-10-20 /pmc/articles/PMC4611143/ /pubmed/26539124 http://dx.doi.org/10.3389/fphys.2015.00287 Text en Copyright © 2015 Hatano, Okada, Washio, Hisada and Sugiura. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Physics Hatano, Asuka Okada, Jun-Ichi Washio, Takumi Hisada, Toshiaki Sugiura, Seiryo An integrated finite element simulation of cardiomyocyte function based on triphasic theory |
title | An integrated finite element simulation of cardiomyocyte function based on triphasic theory |
title_full | An integrated finite element simulation of cardiomyocyte function based on triphasic theory |
title_fullStr | An integrated finite element simulation of cardiomyocyte function based on triphasic theory |
title_full_unstemmed | An integrated finite element simulation of cardiomyocyte function based on triphasic theory |
title_short | An integrated finite element simulation of cardiomyocyte function based on triphasic theory |
title_sort | integrated finite element simulation of cardiomyocyte function based on triphasic theory |
topic | Physics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4611143/ https://www.ncbi.nlm.nih.gov/pubmed/26539124 http://dx.doi.org/10.3389/fphys.2015.00287 |
work_keys_str_mv | AT hatanoasuka anintegratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT okadajunichi anintegratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT washiotakumi anintegratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT hisadatoshiaki anintegratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT sugiuraseiryo anintegratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT hatanoasuka integratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT okadajunichi integratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT washiotakumi integratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT hisadatoshiaki integratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory AT sugiuraseiryo integratedfiniteelementsimulationofcardiomyocytefunctionbasedontriphasictheory |