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Simulation of developmental changes in action potentials with ventricular cell models.

Itoh H, Naito Y, Tomita M - Syst Synth Biol (2007)

Bottom Line: The simulated action potential of the early embryonic ventricular cell model exhibited spontaneous activity, which ceased in the simulated action potential of the late embryonic and neonatal ventricular cell models.The simulations with our models were able to reproduce action potentials that were consistent with the reported characteristics of the cells in vitro.The action potential of rodent ventricular cells at different developmental stages can be reproduced with common sets of mathematical equations by multiplying conductance or conversion factors for ionic currents, pumps, exchangers, and SR Ca(2+) kinetics by relative activities.

View Article: PubMed Central - PubMed

Affiliation: Institute for Advanced Biosciences, Keio University, Fujisawa, Kanagawa, 252-8520, Japan, ducky@sfc.keio.ac.jp.

ABSTRACT
During cardiomyocyte development, early embryonic ventricular cells show spontaneous activity that disappears at a later stage. Dramatic changes in action potential are mediated by developmental changes in individual ionic currents. Hence, reconstruction of the individual ionic currents into an integrated mathematical model would lead to a better understanding of cardiomyocyte development. To simulate the action potential of the rodent ventricular cell at three representative developmental stages, quantitative changes in the ionic currents, pumps, exchangers, and sarcoplasmic reticulum (SR) Ca(2+) kinetics were represented as relative activities, which were multiplied by conductance or conversion factors for individual ionic systems. The simulated action potential of the early embryonic ventricular cell model exhibited spontaneous activity, which ceased in the simulated action potential of the late embryonic and neonatal ventricular cell models. The simulations with our models were able to reproduce action potentials that were consistent with the reported characteristics of the cells in vitro. The action potential of rodent ventricular cells at different developmental stages can be reproduced with common sets of mathematical equations by multiplying conductance or conversion factors for ionic currents, pumps, exchangers, and SR Ca(2+) kinetics by relative activities.

No MeSH data available.


Simulated action potentials at different developmental stages with the constructed models. (A) Simulated action potential at early embryonic stage. (B) Simulated action potential at late embryonic stage (dark line) and neonatal stage (light line). Action potential at adult stage is shown as dashed line
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Fig2: Simulated action potentials at different developmental stages with the constructed models. (A) Simulated action potential at early embryonic stage. (B) Simulated action potential at late embryonic stage (dark line) and neonatal stage (light line). Action potential at adult stage is shown as dashed line

Mentions: The early embryonic ventricular cell model exhibited a spontaneous action potential (Fig. 2A). After the maximum diastolic potential (MDP) at −62.86 mV, the membrane potential slowly depolarized until it reached approximately −40 mV, when spontaneous action potential was triggered. The membrane potential then started to repolarize at 3.13 mV, and completed repolarization in less than 100 ms. The whole action potential was completed in a basic cycle length (BCL) of 492 ms.Fig. 2


Simulation of developmental changes in action potentials with ventricular cell models.

Itoh H, Naito Y, Tomita M - Syst Synth Biol (2007)

Simulated action potentials at different developmental stages with the constructed models. (A) Simulated action potential at early embryonic stage. (B) Simulated action potential at late embryonic stage (dark line) and neonatal stage (light line). Action potential at adult stage is shown as dashed line
© Copyright Policy
Related In: Results  -  Collection

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Fig2: Simulated action potentials at different developmental stages with the constructed models. (A) Simulated action potential at early embryonic stage. (B) Simulated action potential at late embryonic stage (dark line) and neonatal stage (light line). Action potential at adult stage is shown as dashed line
Mentions: The early embryonic ventricular cell model exhibited a spontaneous action potential (Fig. 2A). After the maximum diastolic potential (MDP) at −62.86 mV, the membrane potential slowly depolarized until it reached approximately −40 mV, when spontaneous action potential was triggered. The membrane potential then started to repolarize at 3.13 mV, and completed repolarization in less than 100 ms. The whole action potential was completed in a basic cycle length (BCL) of 492 ms.Fig. 2

Bottom Line: The simulated action potential of the early embryonic ventricular cell model exhibited spontaneous activity, which ceased in the simulated action potential of the late embryonic and neonatal ventricular cell models.The simulations with our models were able to reproduce action potentials that were consistent with the reported characteristics of the cells in vitro.The action potential of rodent ventricular cells at different developmental stages can be reproduced with common sets of mathematical equations by multiplying conductance or conversion factors for ionic currents, pumps, exchangers, and SR Ca(2+) kinetics by relative activities.

View Article: PubMed Central - PubMed

Affiliation: Institute for Advanced Biosciences, Keio University, Fujisawa, Kanagawa, 252-8520, Japan, ducky@sfc.keio.ac.jp.

ABSTRACT
During cardiomyocyte development, early embryonic ventricular cells show spontaneous activity that disappears at a later stage. Dramatic changes in action potential are mediated by developmental changes in individual ionic currents. Hence, reconstruction of the individual ionic currents into an integrated mathematical model would lead to a better understanding of cardiomyocyte development. To simulate the action potential of the rodent ventricular cell at three representative developmental stages, quantitative changes in the ionic currents, pumps, exchangers, and sarcoplasmic reticulum (SR) Ca(2+) kinetics were represented as relative activities, which were multiplied by conductance or conversion factors for individual ionic systems. The simulated action potential of the early embryonic ventricular cell model exhibited spontaneous activity, which ceased in the simulated action potential of the late embryonic and neonatal ventricular cell models. The simulations with our models were able to reproduce action potentials that were consistent with the reported characteristics of the cells in vitro. The action potential of rodent ventricular cells at different developmental stages can be reproduced with common sets of mathematical equations by multiplying conductance or conversion factors for ionic currents, pumps, exchangers, and SR Ca(2+) kinetics by relative activities.

No MeSH data available.