Role of TAT-system in cardiac excitability: investigation in a
quantitative model of a ventricular cardiac cell

a 2002

Role of TAT-system in cardiac excitability: investigation in a quantitative model of a ventricular cardiac cell

PÁSEK, Michal; Georges. CHRISTÉ a Jiří ŠIMURDA

Základní údaje

Originální název

Role of TAT-system in cardiac excitability: investigation in a quantitative model of a ventricular cardiac cell

Autoři

PÁSEK, Michal (203 Česká republika, garant); Georges. CHRISTÉ (250 Francie) a Jiří ŠIMURDA (203 Česká republika)

Vydání

New Frontiers in Basic Cardiovascular Research, 2002

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Obor

30105 Physiology

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Kód RIV

RIV/00216224:14110/02:00007141

Organizační jednotka

Lékařská fakulta

Klíčová slova anglicky

cardiac cell; transverse-axial tubular system; quantitative modelling

Štítky

Cardiac cell, Quantitative modelling, transverse-axial tubular system

Změněno: 1. 4. 2010 11:01, doc. Ing. Michal Pásek, Ph.D.

Anotace

V originále

To explore the effect of the cardiac transverse axial tubular system (TAT-system) on excitability of ventricular cells, we developed a quantitative model incorporating the function of the tubules. The model was based on a modified quantitative description proposed by Luo and Rudy (Circ Res, 1994;74:1071-96). The modifications are summarized in our previous publication (Pásek M. et al. Scripta Medica, 2002;75:179-86). The morphological parameters of the TAT-system were based on the study of Soeller and Cannel (Circ Res, 1999;84:266-75). The time constants of ionic diffusion between the TAT-system and external solution was set to 250 ms for Ca2+ ions and 63 ms for K+ and Na+ ions. The properties of the tubular and peripheral membrane were set according to recently published data. The results of simulations were strongly affected by incorporation of the TAT-system under the conditions of low external [K+]. The model including TAT-system began to produce early after-depolarizations at considerably lower values of external [K+] (1.8 mM at 1 Hz and 1.5 mM at 2 Hz) than the model without TAT-system (2.2 mM at 1 Hz and 1.9 mM at 2 Hz). Its higher stability resulted from higher level of tubular [K+] (versus low external [K+]) that sustained the activation of tubular K-conductances responsible for action potential repolarization and resting voltage. The main transporter underlying the higher level of tubular [K+] was an energy-dependent K+-pump that had to be included into the model to maintain potassium homeostasis. The results predict that the TAT-system may play a significant protective role against cellular arrhythmogenesis.

Návaznosti

GP204/02/D129, projekt VaV

Název: Kvantitativní analýza vlivu tubulárního systému na elektrickou aktivitu srdečních buněk

Investor: Grantová agentura ČR, Kvantitativní analýza vlivu tubulárního systému na elektrickou aktivitu srdečních buněk

Citovat

PÁSEK, Michal; Georges. CHRISTÉ a Jiří ŠIMURDA. Role of TAT-system in cardiac excitability: investigation in a quantitative model of a ventricular cardiac cell. In New Frontiers in Basic Cardiovascular Research. 2002.

@proceedings{483053,
   author = {Pásek, Michal and Christé, Georges. and Šimurda, Jiří},
   booktitle = {New Frontiers in Basic Cardiovascular Research},
   keywords = {cardiac cell; transverse-axial tubular system; quantitative modelling},
   language = {eng},
   title = {Role of TAT-system in cardiac excitability: investigation in a quantitative model of a ventricular cardiac cell},
   year = {2002}
}

TY  - CONF
ID  - 483053
AU  - Pásek, Michal - Christé, Georges. - Šimurda, Jiří
PY  - 2002
TI  - Role of TAT-system in cardiac excitability: investigation in a quantitative model of a ventricular cardiac cell
KW  - cardiac cell
KW  - transverse-axial tubular system
KW  - quantitative modelling
N2  - To explore the effect of the cardiac transverse axial tubular system (TAT-system) on excitability of ventricular cells, we developed a quantitative model incorporating the function of the tubules. The model was based on a modified quantitative description proposed by Luo and Rudy (Circ Res, 1994;74:1071-96). The modifications are summarized in our previous publication (Pásek M. et al. Scripta Medica, 2002;75:179-86). The morphological parameters of the TAT-system were based on the study of Soeller and Cannel (Circ Res, 1999;84:266-75). The time constants of ionic diffusion between the TAT-system and external solution was set to 250 ms for Ca2+ ions and 63 ms for K+ and Na+ ions. The properties of the tubular and peripheral membrane were set according to recently published data. The results of simulations were strongly affected by incorporation of the TAT-system under the conditions of low external [K+]. The model including TAT-system began to produce early after-depolarizations at considerably lower values of external [K+] (1.8 mM at 1 Hz and 1.5 mM at 2 Hz) than the model without TAT-system (2.2 mM at 1 Hz and 1.9 mM at 2 Hz). Its higher stability resulted from higher level of tubular [K+] (versus low external [K+]) that sustained the activation of tubular K-conductances responsible for action potential repolarization and resting voltage. The main transporter underlying the higher level of tubular [K+] was an energy-dependent K+-pump that had to be included into the model to maintain potassium homeostasis. The results predict that the TAT-system may play a significant protective role against cellular arrhythmogenesis.
ER  -

PÁSEK, Michal; Georges. CHRISTÉ a Jiří ŠIMURDA. Role of TAT-system in cardiac excitability: investigation in a quantitative model of a ventricular cardiac cell. In \textit{New Frontiers in Basic Cardiovascular Research}. 2002.

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