Divergent estimates of the ratio between Na+-Ca2+ current
densities in t-tubular and surface membranes of rat ventricular
cardiomyocytes

J 2021

Divergent estimates of the ratio between Na+-Ca2+ current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes

PÁSEK, Michal, Jiří ŠIMURDA, Markéta BÉBAROVÁ and Georges CHRISTE

Basic information

Original name

Divergent estimates of the ratio between Na+-Ca2+ current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes

Authors

PÁSEK, Michal (203 Czech Republic, guarantor, belonging to the institution), Jiří ŠIMURDA (203 Czech Republic, belonging to the institution), Markéta BÉBAROVÁ (203 Czech Republic, belonging to the institution) and Georges CHRISTE (250 France)

Edition

Journal of Cell Science, Cambridge, Company of Biologists Ltd. 2021, 0021-9533

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10601 Cell biology

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

Impact factor

Impact factor: 5.235

RIV identification code

RIV/00216224:14110/21:00120203

Organization unit

Faculty of Medicine

DOI

http://dx.doi.org/10.1242/jcs.258228

UT WoS

000681395800011

Keywords in English

Cardiac myocyte; t-tubules; Na-Ca exchanger; Membrane current density; Log-normal distribution; Monte Carlo simulation

Abstract

V originále

The ratio between Na+-Ca2+ exchange current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes (J(NaCa)-ratio) estimated from electrophysiological data published to date yields strikingly different values between 1.7 and nearly 40. Possible reasons for such divergence were analysed by Monte Carlo simulations assuming both normal and log-normal distribution of the measured data. The confidence intervals CI95 of themean J(NaCa)-ratios computed from the reported data showed an overlap of values between 1 and 3, and between 0.3 and 4.3 in the case of normal and log-normal distribution, respectively. Further analyses revealed that the published high values likely result from a large scatter of data due to transmural differences in J(NaCa), dispersion of cell membrane capacitances and variability in incomplete detubulation. Taking into account the asymmetric distribution of the measured data, the reduction of mean current densities after detubulation and the substantiallysmaller CI95 of lower values of the mean J(NaCa)-ratio, the values between 1.6 and 3.2 may be considered as the most accurate estimates. This implies that 40 to 60% of Na+-Ca2+ exchanger is located at the t-tubular membrane of adult rat ventricular cardiomyocytes.

Links

NV16-30571A, research and development project

Name: Klinický význam a elektrofyziologické zhodnocení mutace c.926C>T genu KCNQ1 (p.T309I) jako možné „founder mutation“ syndromu dlouhého intervalu QT

Citovat

PÁSEK, Michal, Jiří ŠIMURDA, Markéta BÉBAROVÁ and Georges CHRISTE. Divergent estimates of the ratio between Na+-Ca2+ current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes. Journal of Cell Science. Cambridge: Company of Biologists Ltd., 2021, vol. 134, No 14, p. 1-7. ISSN 0021-9533. Available from: https://dx.doi.org/10.1242/jcs.258228.

@article{1818481,
   author = {Pásek, Michal and Šimurda, Jiří and Bébarová, Markéta and Christe, Georges},
   article_location = {Cambridge},
   article_number = {14},
   doi = {http://dx.doi.org/10.1242/jcs.258228},
   keywords = {Cardiac myocyte; t-tubules; Na-Ca exchanger; Membrane current density; Log-normal distribution; Monte Carlo simulation},
   language = {eng},
   issn = {0021-9533},
   journal = {Journal of Cell Science},
   title = {Divergent estimates of the ratio between Na+-Ca2+ current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes},
   url = {https://journals.biologists.com/jcs/article-abstract/134/14/jcs258228/271058/Divergent-estimates-of-the-ratio-between-Na-Ca2?redirectedFrom=fulltext},
   volume = {134},
   year = {2021}
}

TY  - JOUR
ID  - 1818481
AU  - Pásek, Michal - Šimurda, Jiří - Bébarová, Markéta - Christe, Georges
PY  - 2021
TI  - Divergent estimates of the ratio between Na+-Ca2+ current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes
JF  - Journal of Cell Science
VL  - 134
IS  - 14
SP  - 1-7
EP  - 1-7
PB  - Company of Biologists Ltd.
SN  - 00219533
KW  - Cardiac myocyte
KW  - t-tubules
KW  - Na-Ca exchanger
KW  - Membrane current density
KW  - Log-normal distribution
KW  - Monte Carlo simulation
UR  - https://journals.biologists.com/jcs/article-abstract/134/14/jcs258228/271058/Divergent-estimates-of-the-ratio-between-Na-Ca2?redirectedFrom=fulltext
N2  - The ratio between Na+-Ca2+ exchange current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes (J(NaCa)-ratio) estimated from electrophysiological data published to date yields strikingly different values between 1.7 and nearly 40. Possible reasons for such divergence were analysed by Monte Carlo simulations assuming both normal and log-normal distribution of the measured data. The confidence intervals CI95 of themean J(NaCa)-ratios computed from the reported data showed an overlap of values between 1 and 3, and between 0.3 and 4.3 in the case of normal and log-normal distribution, respectively. Further analyses revealed that the published high values likely result from a large scatter of data due to transmural differences in J(NaCa), dispersion of cell membrane capacitances and variability in incomplete detubulation. Taking into account the asymmetric distribution of the measured data, the reduction of mean current densities after detubulation and the substantiallysmaller CI95 of lower values of the mean J(NaCa)-ratio, the values between 1.6 and 3.2 may be considered as the most accurate estimates. This implies that 40 to 60% of Na+-Ca2+ exchanger is located at the t-tubular membrane of adult rat ventricular cardiomyocytes.
ER  -

PÁSEK, Michal, Jiří ŠIMURDA, Markéta BÉBAROVÁ and Georges CHRISTE. Divergent estimates of the ratio between Na+-Ca2+ current densities in t-tubular and surface membranes of rat ventricular cardiomyocytes. \textit{Journal of Cell Science}. Cambridge: Company of Biologists Ltd., 2021, vol.~134, No~14, p.~1-7. ISSN~0021-9533. Available from: https://dx.doi.org/10.1242/jcs.258228.

Detailed Information on Publication Record