| PÁSEK, Michal, Jiří ŠIMURDA, Clive ORCHARD and Georges CHRISTÉ. Quantitative exploration of T-tubular membrane parameters in a model of rat ventricular cardiomyocyte. Journal of Molecular and Cellular Cardiology. Elsevier Ltd., 2005, vol. 39, No 1, p. 177-178. ISSN 0022-2828. |
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@article{622348,
author = {Pásek, Michal and Šimurda, Jiří and Orchard, Clive and Christé, Georges},
article_number = {1},
keywords = {cardiac cell; tubular system; quantitative modelling},
language = {eng},
issn = {0022-2828},
journal = {Journal of Molecular and Cellular Cardiology},
title = {Quantitative exploration of T-tubular membrane parameters in a model of rat ventricular cardiomyocyte},
volume = {39},
year = {2005}
}
TY - JOUR
ID - 622348
AU - Pásek, Michal - Šimurda, Jiří - Orchard, Clive - Christé, Georges
PY - 2005
TI - Quantitative exploration of T-tubular membrane parameters in a model of rat ventricular cardiomyocyte
JF - Journal of Molecular and Cellular Cardiology
VL - 39
IS - 1
SP - 177-178
EP - 177-178
PB - Elsevier Ltd.
SN - 00222828
KW - cardiac cell
KW - tubular system
KW - quantitative modelling
N2 - Formamide-induced detubulation of rat ventricular cardiac myocytes causes an ~32% decrease of membrane capacitance (Despa et al, 2003). Detailed microscopic analysis of the transverse-axial tubular system (TATS) by Soeller and Cannel (1999) showed a mean tubule diameter of 255 nm, a mean segment length of 6.87 ľm, a tubule density of 0.3 ľm-2, fractional volume of 3.6% and TATS membrane area to cell volume ratio of 0.44 ľm2/ľm3. These parameters can be approximately respected when the fraction of the total sarcolemma within the TATS is 56%. To explore possible causes for this discrepancy we used a quantitative model of the rat ventricular myocyte that included a description of TATS. Two explanations were found that could account quantitatively for the discrepancy: (i) incomplete detubulation leaving electrical access to a large area of TATS membrane, due to the branched TATS network. The estimate of Despa et al. could be met if 42% of TATS remained accessible after detubulation. (ii) the specific membrane capacitance of TATS membrane is lower than that of the surface sarcolemma (set to 1 ľFcm-2). Such a difference may result from the different composition of the two membranes. To account for the discrepancy, the specific capacitance of the TATS membrane must be decreased to 0.37 ľF.cm-2. A combination of both explanations may contribute to the observed discrepancy, e.g. 15% TATS membrane area remaining accessible with specific capacitance of 0.47 ľF.cm-2.
ER -
PÁSEK, Michal, Jiří ŠIMURDA, Clive ORCHARD and Georges CHRISTÉ. Quantitative exploration of T-tubular membrane parameters in a model of rat ventricular cardiomyocyte. \textit{Journal of Molecular and Cellular Cardiology}. Elsevier Ltd., 2005, vol.~39, No~1, p.~177-178. ISSN~0022-2828.
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