Current density as routine parameter for description of ionic
membrane current: is it always the best option?

J 2020

Current density as routine parameter for description of ionic membrane current: is it always the best option?

KULA, Roman; Markéta BÉBAROVÁ; Peter MATEJOVIČ; Jiří ŠIMURDA; Michal PÁSEK et. al.

Basic information

Original name

Current density as routine parameter for description of ionic membrane current: is it always the best option?

Authors

KULA, Roman (203 Czech Republic, belonging to the institution); Markéta BÉBAROVÁ (203 Czech Republic, guarantor, belonging to the institution); Peter MATEJOVIČ (203 Czech Republic, belonging to the institution); Jiří ŠIMURDA (203 Czech Republic, belonging to the institution) and Michal PÁSEK (203 Czech Republic, belonging to the institution)

Edition

PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY, OXFORD, PERGAMON-ELSEVIER SCIENCE LTD, 2020, 0079-6107

Other information

Language

English

Type of outcome

Article in a journal

Field of Study

10608 Biochemistry and molecular biology

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

is not subject to a state or trade secret

References:

URL

Impact factor

Impact factor: 3.667

RIV identification code

RIV/00216224:14110/20:00118627

Organization unit

Faculty of Medicine

DOI

https://doi.org/10.1016/j.pbiomolbio.2019.11.011

UT WoS

000582745400005

EID Scopus

2-s2.0-85076566566

Keywords in English

Ionic current; Current density; Current-capacitance correlation; Current-capacitance proportionality; Rat cardiomyocyte; Normalisation by ratio

Abstract

In the original language

The current density (J) is a parameter routinely used to characterize individual ionic membrane currents. Its evaluation is based on the presumption that the magnitude of whole-cell ionic membrane current (I) is directly proportional to the cell membrane capacitance (C), i.e. I positively and strongly correlates with C and the regression line describing I-C relation intersects the y-axis close to the origin of coordinates. We aimed to prove the presumption in several examples and find whether the conversion of I to J could be always beneficial. I-C relation was analysed in several potassium currents, measured in rat atrial myocytes (in inward rectifier currents, I-K1, and both the constitutively active and acetylcholine-induced components of acetylcholine-sensitive current, I-K(Ach)CONST and I-K(Ach)ACH), and in rat ventricular myocytes (transient outward current I-to). I-C correlation was estimated by the Pearson coefficient (r). A coefficient (k) was newly suggested describing deviation of the regression intercept from zero in currents with considerable r value. Based on mathematical simulations, I was satisfactorily proportional to C when r >= 0.6 and k <= 0.2 which was fulfilled in I-K1 and I-K(Ach)ACH (r = 0.84, k = 0.20, and r = 0.61, k = 0.06, respectively). IeC correlation was significantly positive, but weak in I-K(Ach)CONST (r = 0.42), and virtually missing in Ito (r = 0.04). The impaired I-C proportionality in I-K(Ach)CONST and Ito likely reflects heterogeneity of the channel expression. We conclude that the conversion of I to J should be avoided when I-C proportionality is absent. Otherwise, serious misinterpretation of data may arise. (C) 2019 Elsevier Ltd. All rights reserved.

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

Cite

KULA, Roman; Markéta BÉBAROVÁ; Peter MATEJOVIČ; Jiří ŠIMURDA and Michal PÁSEK. Current density as routine parameter for description of ionic membrane current: is it always the best option? PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD, 2020, vol. 157, NOV 2020, p. 24-32. ISSN 0079-6107. Available from: https://doi.org/10.1016/j.pbiomolbio.2019.11.011.

@article{1692064,
   author = {Kula, Roman and Bébarová, Markéta and Matejovič, Peter and Šimurda, Jiří and Pásek, Michal},
   article_location = {OXFORD},
   article_number = {NOV 2020},
   doi = {https://doi.org/10.1016/j.pbiomolbio.2019.11.011},
   keywords = {Ionic current; Current density; Current-capacitance correlation; Current-capacitance proportionality; Rat cardiomyocyte; Normalisation by ratio},
   language = {eng},
   issn = {0079-6107},
   journal = {PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY},
   title = {Current density as routine parameter for description of ionic membrane current: is it always the best option?},
   url = {https://www.sciencedirect.com/science/article/pii/S0079610719301452?via%3Dihub},
   volume = {157},
   year = {2020}
}

TY  - JOUR
ID  - 1692064
AU  - Kula, Roman - Bébarová, Markéta - Matejovič, Peter - Šimurda, Jiří - Pásek, Michal
PY  - 2020
TI  - Current density as routine parameter for description of ionic membrane current: is it always the best option?
JF  - PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY
VL  - 157
IS  - NOV 2020
SP  - 24-32
EP  - 24-32
PB  - PERGAMON-ELSEVIER SCIENCE LTD
SN  - 00796107
KW  - Ionic current
KW  - Current density
KW  - Current-capacitance correlation
KW  - Current-capacitance proportionality
KW  - Rat cardiomyocyte
KW  - Normalisation by ratio
UR  - https://www.sciencedirect.com/science/article/pii/S0079610719301452?via%3Dihub
L2  - https://www.sciencedirect.com/science/article/pii/S0079610719301452?via%3Dihub
N2  - The current density (J) is a parameter routinely used to characterize individual ionic membrane currents. Its evaluation is based on the presumption that the magnitude of whole-cell ionic membrane current (I) is directly proportional to the cell membrane capacitance (C), i.e. I positively and strongly correlates with C and the regression line describing I-C relation intersects the y-axis close to the origin of coordinates. We aimed to prove the presumption in several examples and find whether the conversion of I to J could be always beneficial. I-C relation was analysed in several potassium currents, measured in rat atrial myocytes (in inward rectifier currents, I-K1, and both the constitutively active and acetylcholine-induced components of acetylcholine-sensitive current, I-K(Ach)CONST and I-K(Ach)ACH), and in rat ventricular myocytes (transient outward current I-to). I-C correlation was estimated by the Pearson coefficient (r). A coefficient (k) was newly suggested describing deviation of the regression intercept from zero in currents with considerable r value. Based on mathematical simulations, I was satisfactorily proportional to C when r >= 0.6 and k <= 0.2 which was fulfilled in I-K1 and I-K(Ach)ACH (r = 0.84, k = 0.20, and r = 0.61, k = 0.06, respectively). IeC correlation was significantly positive, but weak in I-K(Ach)CONST (r = 0.42), and virtually missing in Ito (r = 0.04). The impaired I-C proportionality in I-K(Ach)CONST and Ito likely reflects heterogeneity of the channel expression. We conclude that the conversion of I to J should be avoided when I-C proportionality is absent. Otherwise, serious misinterpretation of data may arise. (C) 2019 Elsevier Ltd. All rights reserved.
ER  -

KULA, Roman; Markéta BÉBAROVÁ; Peter MATEJOVIČ; Jiří ŠIMURDA and Michal PÁSEK. Current density as routine parameter for description of ionic membrane current: is it always the best option? \textit{PROGRESS IN BIOPHYSICS \&{}amp; MOLECULAR BIOLOGY}. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD, 2020, vol.~157, NOV 2020, p.~24-32. ISSN~0079-6107. Available from: https://doi.org/10.1016/j.pbiomolbio.2019.11.011.

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