지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
논문 기본 정보
- 자료유형
- 학술저널
- 저자정보
- 발행연도
- 2011.1
- 수록면
- 211 - 219 (9page)
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초록· 키워드
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Recent evidence indicates that the voltage clock (cyclic activation and deactivation of membrane ion channels) and Ca^(2+) clocks (rhythmic spontaneous sarcoplasmic reticulum Ca^(2+) release) jointly regulate sinoatrial node (SAN) automaticity. However,the relative importance of the voltage clock and Ca^(2+) clock for pacemaking was not revealed in sick sinus syndrome. Previously, we mapped the intracellular calcium (Cai) and membrane potentials of the normal intact SAN simultaneously using optical mapping in Langendorff-perfused canine right atrium. We demonstrated that the sinus rate increased and the leading pacemaker shifted to the superior SAN with robust late diastolic Cai elevation (LDCAE) during β-adrenergic stimulation. We also showed that the LDCAE was caused by spontaneous diastolic sarcoplasmic reticulum (SR) Ca^(2+) release and was closely related to heart rate changes. In contrast, in pacing induced canine atrial fibrillation and SAN dysfunction models, Ca^(2+ )clock of SAN was unresponsiveness to β-adrenergic stimulation and caffeine. Ryanodine receptor 2 (RyR2) in SAN was down-regulated. Using the prolonged low dose isoproterenol together with funny current block, we produced a tachybradycardia model. In this model, chronically elevated sympathetic tone results in abnormal pacemaking hierarchy in the right atrium, including suppression of the superior SAN and enhanced pacemaking from ectopic sites. Finally,if the LDCAE was too small to trigger an action potential, then it induced only delayed afterdepolarization (DAD)-like diastolic depolarization (DD). The failure of DAD-like DD to consistently trigger a sinus beat is a novel mechanism of atrial arrhythmogenesis. We conclude that dysfunction of both the Ca^(2+) clock and the voltage clock are important in sick sinus syndrome.
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참고문헌 (25)
참고문헌 신청
Adan V / 2003 / Diagnosis and treatment of sick sinus syndrome / Am Fam Physician 67 : 1725 ~ 1732
Baruscotti M / 2005 / Physiology and pharmacology of the cardiac pacemaker (“funny”) current / Pharmacol Ther 107 : 59 ~ 79
Bhuiyan ZA / 2007 / Expanding spectrum of human TYR2-related disease: new electrocardiographic, structural, and genetic features / Circulation 116 : 1569 ~ 1576
Boineau JP / 1978 / Multicentric origin of the atrial depolarization wave: the pacemaker complex. Relation to dynamics of atrial conduction, P-wave changes and heart rate co
Boineau JP / 1984 / Activation sequence and potential distribution maps demonstrating multicentric atrial impulse origin in dogs / Circ Res 54 : 332 ~ 347
Baruscotti M / 2005 / Physiology and pharmacology of the cardiac pacemaker (“funny”) current / Pharmacol Ther 107 : 59 ~ 79
Bhuiyan ZA / 2007 / Expanding spectrum of human TYR2-related disease: new electrocardiographic, structural, and genetic features / Circulation 116 : 1569 ~ 1576
Boineau JP / 1978 / Multicentric origin of the atrial depolarization wave: the pacemaker complex. Relation to dynamics of atrial conduction, P-wave changes and heart rate co
Boineau JP / 1984 / Activation sequence and potential distribution maps demonstrating multicentric atrial impulse origin in dogs / Circ Res 54 : 332 ~ 347
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