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T-type calcium current in electrical activity of cardiomyocytes isolated from rabbit pulmonary vein.
J Cardiovasc Electrophysiol. 2004 May; 15(5):567-71.JC

Abstract

INTRODUCTION

Pulmonary veins (PVs) are known to initiate paroxysmal atrial fibrillation. T-type calcium current (I(Ca-T)) has a role in normal and abnormal automaticity of cardiomyocytes. The aim of this study was to evaluate whether I(Ca-T) contributes to PV electrical activity.

METHODS AND RESULTS

By whole-cell clamp techniques in rabbit myocytes, I(Ca-T) was identified in 12 (39%) of 31 PV cardiomyocytes with pacemaker activity, 2 (9%) of 23 PV cardiomyocytes without pacemaker activity, and 2 (15%) of 13 atrial myocytes (P < 0.05). Maximum I(Ca-L) and I(Ca-T) densities from PV cardiomyocytes with pacemaker activity were 6.87 +/- 2.17 pA/pF and 1.38 +/- 0.69 pA/pF, respectively. Nickel (40 microM) decreased the spontaneous activity in 5 (36%) of 14 PV cardiomyocytes (3.1 +/- 0.6 Hz vs 2.2 +/- 0.5 Hz, P < 0.05), reduced the amplitudes of delayed after depolarization from 13 +/- 1 mV to 7 +/- 1 mV (n = 4, P < 0.05) and inhibited transient inward currents from 1.2 +/- 0.2 pA/pF to 0.7 +/- 0.1 pA/pF (n = 11, P < 0.01).

CONCLUSIONS

We conclude that I(Ca-T) contributes to PV pacemaker activity and triggered activity, which are of functional importance in PV arrhythmogenesis.

Authors+Show Affiliations

Chen YC
Department of Biomedical Engineering, National Defense Medical Center, Taiwan, Republic of China.
Chen SA
No affiliation info available
Chen YJ
No affiliation info available
Tai CT
No affiliation info available
Chan P
No affiliation info available
Lin CI
No affiliation info available

MeSH

Action PotentialsAnimalsBiological ClocksCalcium Channels, T-TypeCells, CulturedMembrane PotentialsMyocytes, CardiacNickelPulmonary VeinsRabbits

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15149427

Citation

Chen, Yao-Chang, et al. "T-type Calcium Current in Electrical Activity of Cardiomyocytes Isolated From Rabbit Pulmonary Vein." Journal of Cardiovascular Electrophysiology, vol. 15, no. 5, 2004, pp. 567-71.
Chen YC, Chen SA, Chen YJ, et al. T-type calcium current in electrical activity of cardiomyocytes isolated from rabbit pulmonary vein. J Cardiovasc Electrophysiol. 2004;15(5):567-71.
Chen, Y. C., Chen, S. A., Chen, Y. J., Tai, C. T., Chan, P., & Lin, C. I. (2004). T-type calcium current in electrical activity of cardiomyocytes isolated from rabbit pulmonary vein. Journal of Cardiovascular Electrophysiology, 15(5), 567-71.
Chen YC, et al. T-type Calcium Current in Electrical Activity of Cardiomyocytes Isolated From Rabbit Pulmonary Vein. J Cardiovasc Electrophysiol. 2004;15(5):567-71. PubMed PMID: 15149427.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - T-type calcium current in electrical activity of cardiomyocytes isolated from rabbit pulmonary vein. AU - Chen,Yao-Chang, AU - Chen,Shih-Ann, AU - Chen,Yi-Jen, AU - Tai,Ching-Tai, AU - Chan,Paul, AU - Lin,Cheng-I, PY - 2004/5/20/pubmed PY - 2004/9/2/medline PY - 2004/5/20/entrez SP - 567 EP - 71 JF - Journal of cardiovascular electrophysiology JO - J Cardiovasc Electrophysiol VL - 15 IS - 5 N2 - INTRODUCTION: Pulmonary veins (PVs) are known to initiate paroxysmal atrial fibrillation. T-type calcium current (I(Ca-T)) has a role in normal and abnormal automaticity of cardiomyocytes. The aim of this study was to evaluate whether I(Ca-T) contributes to PV electrical activity. METHODS AND RESULTS: By whole-cell clamp techniques in rabbit myocytes, I(Ca-T) was identified in 12 (39%) of 31 PV cardiomyocytes with pacemaker activity, 2 (9%) of 23 PV cardiomyocytes without pacemaker activity, and 2 (15%) of 13 atrial myocytes (P < 0.05). Maximum I(Ca-L) and I(Ca-T) densities from PV cardiomyocytes with pacemaker activity were 6.87 +/- 2.17 pA/pF and 1.38 +/- 0.69 pA/pF, respectively. Nickel (40 microM) decreased the spontaneous activity in 5 (36%) of 14 PV cardiomyocytes (3.1 +/- 0.6 Hz vs 2.2 +/- 0.5 Hz, P < 0.05), reduced the amplitudes of delayed after depolarization from 13 +/- 1 mV to 7 +/- 1 mV (n = 4, P < 0.05) and inhibited transient inward currents from 1.2 +/- 0.2 pA/pF to 0.7 +/- 0.1 pA/pF (n = 11, P < 0.01). CONCLUSIONS: We conclude that I(Ca-T) contributes to PV pacemaker activity and triggered activity, which are of functional importance in PV arrhythmogenesis. SN - 1045-3873 UR - https://www.unboundmedicine.com/medline/citation/15149427/T_type_calcium_current_in_electrical_activity_of_cardiomyocytes_isolated_from_rabbit_pulmonary_vein_ DB - PRIME DP - Unbound Medicine ER -