The calcium and voltage clocks in sinoatrial node automaticity

Boyoung Joung, Masahiro Ogawa, Shien Fong Lin, Peng Sheng Chen

Research output: Contribution to journalReview article

14 Citations (Scopus)

Abstract

Recent evidence indicates that the voltage (cyclic activation and deactivation of membrane ion channels) and Ca2+ clocks (rhythmic spontaneous sarcoplasmic reticulum Ca2+ release) jointly regulate sinoatrial node (SAN) automaticity. Since the intact SAN is a heterogeneous structure that includes multiple different cell types interacting with each other, the relative importance of the voltage and Ca2+ clocks for pacemaking may be variable in different regions of the SAN. Recently, we performed optical mapping in isolated and Langendorff-perfused canine right atria. We mapped the intracellular calcium (Cai) and membrane potentials of the intact SAN simultaneously. Using previously described criteria of the timing of the late diastolic Cai elevation (LDCAE) relative to the action potential upstroke to detect Ca2+ clock activity, we demonstrated that the sinus rate increased and the leading pacemaker shifted to the superior SAN with the robust LDCAE during β-adrenergic stimulation. We also showed that the LDCAE was caused by spontaneous diastolic SR Ca 2+ release and was closely related with heart rate changes. We conclude that the Ca and voltage clocks work synergistically to generate SAN automaticity.

Original languageEnglish (US)
Pages (from-to)217-222
Number of pages6
JournalKorean Circulation Journal
Volume39
Issue number6
DOIs
StatePublished - Jun 1 2009

Fingerprint

Sinoatrial Node
Calcium
Ion Channels
Intracellular Membranes
Sarcoplasmic Reticulum
Heart Atria
Adrenergic Agents
Membrane Potentials
Action Potentials
Canidae
Heart Rate

Keywords

  • Calcium
  • Sarcoplasmic reticulum
  • Sinoatrial node
  • Sympathetic nervous system

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Internal Medicine

Cite this

The calcium and voltage clocks in sinoatrial node automaticity. / Joung, Boyoung; Ogawa, Masahiro; Lin, Shien Fong; Chen, Peng Sheng.

In: Korean Circulation Journal, Vol. 39, No. 6, 01.06.2009, p. 217-222.

Research output: Contribution to journalReview article

@article{fbfeaccc4aec49c1ba8299f9bdd400df,
title = "The calcium and voltage clocks in sinoatrial node automaticity",
abstract = "Recent evidence indicates that the voltage (cyclic activation and deactivation of membrane ion channels) and Ca2+ clocks (rhythmic spontaneous sarcoplasmic reticulum Ca2+ release) jointly regulate sinoatrial node (SAN) automaticity. Since the intact SAN is a heterogeneous structure that includes multiple different cell types interacting with each other, the relative importance of the voltage and Ca2+ clocks for pacemaking may be variable in different regions of the SAN. Recently, we performed optical mapping in isolated and Langendorff-perfused canine right atria. We mapped the intracellular calcium (Cai) and membrane potentials of the intact SAN simultaneously. Using previously described criteria of the timing of the late diastolic Cai elevation (LDCAE) relative to the action potential upstroke to detect Ca2+ clock activity, we demonstrated that the sinus rate increased and the leading pacemaker shifted to the superior SAN with the robust LDCAE during β-adrenergic stimulation. We also showed that the LDCAE was caused by spontaneous diastolic SR Ca 2+ release and was closely related with heart rate changes. We conclude that the Ca and voltage clocks work synergistically to generate SAN automaticity.",
keywords = "Calcium, Sarcoplasmic reticulum, Sinoatrial node, Sympathetic nervous system",
author = "Boyoung Joung and Masahiro Ogawa and Lin, {Shien Fong} and Chen, {Peng Sheng}",
year = "2009",
month = "6",
day = "1",
doi = "10.4070/kcj.2009.39.6.217",
language = "English (US)",
volume = "39",
pages = "217--222",
journal = "Korean Circulation Journal",
issn = "1738-5520",
publisher = "Korean Society of Circulation",
number = "6",

}

TY - JOUR

T1 - The calcium and voltage clocks in sinoatrial node automaticity

AU - Joung, Boyoung

AU - Ogawa, Masahiro

AU - Lin, Shien Fong

AU - Chen, Peng Sheng

PY - 2009/6/1

Y1 - 2009/6/1

N2 - Recent evidence indicates that the voltage (cyclic activation and deactivation of membrane ion channels) and Ca2+ clocks (rhythmic spontaneous sarcoplasmic reticulum Ca2+ release) jointly regulate sinoatrial node (SAN) automaticity. Since the intact SAN is a heterogeneous structure that includes multiple different cell types interacting with each other, the relative importance of the voltage and Ca2+ clocks for pacemaking may be variable in different regions of the SAN. Recently, we performed optical mapping in isolated and Langendorff-perfused canine right atria. We mapped the intracellular calcium (Cai) and membrane potentials of the intact SAN simultaneously. Using previously described criteria of the timing of the late diastolic Cai elevation (LDCAE) relative to the action potential upstroke to detect Ca2+ clock activity, we demonstrated that the sinus rate increased and the leading pacemaker shifted to the superior SAN with the robust LDCAE during β-adrenergic stimulation. We also showed that the LDCAE was caused by spontaneous diastolic SR Ca 2+ release and was closely related with heart rate changes. We conclude that the Ca and voltage clocks work synergistically to generate SAN automaticity.

AB - Recent evidence indicates that the voltage (cyclic activation and deactivation of membrane ion channels) and Ca2+ clocks (rhythmic spontaneous sarcoplasmic reticulum Ca2+ release) jointly regulate sinoatrial node (SAN) automaticity. Since the intact SAN is a heterogeneous structure that includes multiple different cell types interacting with each other, the relative importance of the voltage and Ca2+ clocks for pacemaking may be variable in different regions of the SAN. Recently, we performed optical mapping in isolated and Langendorff-perfused canine right atria. We mapped the intracellular calcium (Cai) and membrane potentials of the intact SAN simultaneously. Using previously described criteria of the timing of the late diastolic Cai elevation (LDCAE) relative to the action potential upstroke to detect Ca2+ clock activity, we demonstrated that the sinus rate increased and the leading pacemaker shifted to the superior SAN with the robust LDCAE during β-adrenergic stimulation. We also showed that the LDCAE was caused by spontaneous diastolic SR Ca 2+ release and was closely related with heart rate changes. We conclude that the Ca and voltage clocks work synergistically to generate SAN automaticity.

KW - Calcium

KW - Sarcoplasmic reticulum

KW - Sinoatrial node

KW - Sympathetic nervous system

UR - http://www.scopus.com/inward/record.url?scp=67651018295&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67651018295&partnerID=8YFLogxK

U2 - 10.4070/kcj.2009.39.6.217

DO - 10.4070/kcj.2009.39.6.217

M3 - Review article

C2 - 19949626

AN - SCOPUS:67651018295

VL - 39

SP - 217

EP - 222

JO - Korean Circulation Journal

JF - Korean Circulation Journal

SN - 1738-5520

IS - 6

ER -