Hydrogen peroxide modulates electrophysiological characteristics of left atrial myocytes

Shih Yu Huang; Yen Yu Lu; Yao Chang Chen; Wei Ta Chen; Yung Kuo Lin; Shih Ann Chen; Yi Jen Chen

Hydrogen peroxide modulates electrophysiological characteristics of left atrial myocytes

Shih Yu Huang, Yen Yu Lu, Yao Chang Chen, Wei Ta Chen, Yung Kuo Lin, Shih Ann Chen, Yi Jen Chen

Research output: Contribution to journal › Article › peer-review

Abstract

Background: Oxidative stress plays an important role in the pathophysiology of atrial fibrillation (AF). The hydrogen peroxide (H₂O₂) mainly underlies the cellular oxidative stress and free radicals. Left atrium (LA) is the most important AF substrate. However, the effects of H ₂O₂ on the action potential (AP) and ionic currents in LA myocytes have not been fully elucidated. Methods: The whole-cell patch clamp was used to investigate the APs and ionic currents of L-type calcium current (I_Ca-L), transient outward currents (I_to), ultra-rapid delayed rectifier potassium current (I_Kur), delayed rectifier potassium currents (I_K), inward rectifier potassium current (I _K1), and sodium-calcium exchanger (NCX) before and after H ₂O₂ (100 μM) in isolated rabbit LA myocytes. Results: H₂O₂ (100 μM) shortened by 50% (from40 ± 7 to 21 ± 5ms) and 90% the AP duration (from 95 ± 12 to 74 ± 11 ms) in LA myocytes (n = 9), but did not change the resting membrane potentials. The H₂O₂ (100 μM) decreased I_to, but increased I_Kur and I_K. H₂O₂ (100 μM) also reduced the I_Ca-L and the reverse mode NCX. However, H₂O₂ (100 μM) did not change I_K1. Conclusions: H₂O₂ directly modulated the APmorphology and ionic currents in LAmyocytes, which may contribute to the genesis of AF in oxidative stress.

Original language	English
Pages (from-to)	38-45
Number of pages	8
Journal	Acta Cardiologica Sinica
Volume	30
Issue number	1
Publication status	Published - Jan 2014

Keywords

Action potential
Ionic current
Oxidative stress

ASJC Scopus subject areas

Cardiology and Cardiovascular Medicine

Cite this

@article{00c2a26dd8eb4db192dc4cc90ee9ec13,

title = "Hydrogen peroxide modulates electrophysiological characteristics of left atrial myocytes",

abstract = "Background: Oxidative stress plays an important role in the pathophysiology of atrial fibrillation (AF). The hydrogen peroxide (H2O2) mainly underlies the cellular oxidative stress and free radicals. Left atrium (LA) is the most important AF substrate. However, the effects of H 2O2 on the action potential (AP) and ionic currents in LA myocytes have not been fully elucidated. Methods: The whole-cell patch clamp was used to investigate the APs and ionic currents of L-type calcium current (ICa-L), transient outward currents (Ito), ultra-rapid delayed rectifier potassium current (IKur), delayed rectifier potassium currents (IK), inward rectifier potassium current (I K1), and sodium-calcium exchanger (NCX) before and after H 2O2 (100 μM) in isolated rabbit LA myocytes. Results: H2O2 (100 μM) shortened by 50% (from40 ± 7 to 21 ± 5ms) and 90% the AP duration (from 95 ± 12 to 74 ± 11 ms) in LA myocytes (n = 9), but did not change the resting membrane potentials. The H2O2 (100 μM) decreased Ito, but increased IKur and IK. H2O2 (100 μM) also reduced the ICa-L and the reverse mode NCX. However, H2O2 (100 μM) did not change IK1. Conclusions: H2O2 directly modulated the APmorphology and ionic currents in LAmyocytes, which may contribute to the genesis of AF in oxidative stress.",

keywords = "Action potential, Ionic current, Oxidative stress",

author = "Huang, {Shih Yu} and Lu, {Yen Yu} and Chen, {Yao Chang} and Chen, {Wei Ta} and Lin, {Yung Kuo} and Chen, {Shih Ann} and Chen, {Yi Jen}",

year = "2014",

month = jan,

language = "English",

volume = "30",

pages = "38--45",

journal = "Acta Cardiologica Sinica",

issn = "1011-6842",

publisher = "Republic of China Society of Cardiology",

number = "1",

}

TY - JOUR

T1 - Hydrogen peroxide modulates electrophysiological characteristics of left atrial myocytes

AU - Huang, Shih Yu

AU - Lu, Yen Yu

AU - Chen, Yao Chang

AU - Chen, Wei Ta

AU - Lin, Yung Kuo

AU - Chen, Shih Ann

AU - Chen, Yi Jen

PY - 2014/1

Y1 - 2014/1

N2 - Background: Oxidative stress plays an important role in the pathophysiology of atrial fibrillation (AF). The hydrogen peroxide (H2O2) mainly underlies the cellular oxidative stress and free radicals. Left atrium (LA) is the most important AF substrate. However, the effects of H 2O2 on the action potential (AP) and ionic currents in LA myocytes have not been fully elucidated. Methods: The whole-cell patch clamp was used to investigate the APs and ionic currents of L-type calcium current (ICa-L), transient outward currents (Ito), ultra-rapid delayed rectifier potassium current (IKur), delayed rectifier potassium currents (IK), inward rectifier potassium current (I K1), and sodium-calcium exchanger (NCX) before and after H 2O2 (100 μM) in isolated rabbit LA myocytes. Results: H2O2 (100 μM) shortened by 50% (from40 ± 7 to 21 ± 5ms) and 90% the AP duration (from 95 ± 12 to 74 ± 11 ms) in LA myocytes (n = 9), but did not change the resting membrane potentials. The H2O2 (100 μM) decreased Ito, but increased IKur and IK. H2O2 (100 μM) also reduced the ICa-L and the reverse mode NCX. However, H2O2 (100 μM) did not change IK1. Conclusions: H2O2 directly modulated the APmorphology and ionic currents in LAmyocytes, which may contribute to the genesis of AF in oxidative stress.

AB - Background: Oxidative stress plays an important role in the pathophysiology of atrial fibrillation (AF). The hydrogen peroxide (H2O2) mainly underlies the cellular oxidative stress and free radicals. Left atrium (LA) is the most important AF substrate. However, the effects of H 2O2 on the action potential (AP) and ionic currents in LA myocytes have not been fully elucidated. Methods: The whole-cell patch clamp was used to investigate the APs and ionic currents of L-type calcium current (ICa-L), transient outward currents (Ito), ultra-rapid delayed rectifier potassium current (IKur), delayed rectifier potassium currents (IK), inward rectifier potassium current (I K1), and sodium-calcium exchanger (NCX) before and after H 2O2 (100 μM) in isolated rabbit LA myocytes. Results: H2O2 (100 μM) shortened by 50% (from40 ± 7 to 21 ± 5ms) and 90% the AP duration (from 95 ± 12 to 74 ± 11 ms) in LA myocytes (n = 9), but did not change the resting membrane potentials. The H2O2 (100 μM) decreased Ito, but increased IKur and IK. H2O2 (100 μM) also reduced the ICa-L and the reverse mode NCX. However, H2O2 (100 μM) did not change IK1. Conclusions: H2O2 directly modulated the APmorphology and ionic currents in LAmyocytes, which may contribute to the genesis of AF in oxidative stress.

KW - Action potential

KW - Ionic current

KW - Oxidative stress

UR - http://www.scopus.com/inward/record.url?scp=84898427928&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84898427928&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:84898427928

SN - 1011-6842

VL - 30

SP - 38

EP - 45

JO - Acta Cardiologica Sinica

JF - Acta Cardiologica Sinica

IS - 1

ER -

Hydrogen peroxide modulates electrophysiological characteristics of left atrial myocytes

Abstract

Keywords

ASJC Scopus subject areas

Other files and links

Fingerprint

Cite this