Action Potential Duration-Stabilizing Action of Taurien in Guinea Pig Ventricular Myocytes
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概要
- 論文の詳細を見る
To examine taurine actions on the rate of repolarization of action potentials (AP), L-type Ca<SUP>2+</SUP> (I<SUB>ca</SUB>), late outward K<SUP>+</SUP> (I<SUB>K</SUB>) and the inward rectifier currents as affected by the external Ca<SUP>2+</SUP> concentrations ([Ca<SUP>2+</SUP>]<SUB>o</SUB>), whole-cell voltage-clamp and current-clamp experiments were conducted in guinea pig ventricular myocytes. At a high (3.6 mM) [Ca<SUP>2+</SUP>]<SUB>o</SUB>, 10 mM taurine suppressed both I<SUB>ca</SUB> and I<SUB>K</SUB>, shortened AP duration and decelerated the rate (−dV/dt) of terminal repolarization of AP. In contrast, at a low (0.9 mM) [Ca<SUP>2+</SUP>]<SUB>o</SUB>, taurine intensified both I<SUB>ca</SUB> and I<SUB>K</SUB>, lengthened AP duration and accelerated −dV/dt. However, at either [Ca<SUP>2+</SUP>]<SUB>o</SUB>, the resting membrane potential was slightly hyperpolarized, and the inward rectifier current examined by the ramp-pulse protocol remained unaffected by taurine. Taurine is suggested to maintain a stable AP duration by altering the inward Ca<SUP>2+</SUP> and I<SUB>K</SUB> in the opposite directions, depending on [Ca<SUP>2+</SUP>]<SUB>o</SUB>. The relevance of the stabilizing action of taurine on the AP duration to its reported antiarrhythmic efficacies is discussed.
- 社団法人 日本薬理学会の論文
- 1996-04-01
著者
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SPERELAKIS Nicholas
Department of Molecular and Cellular Physiology, College of Medicine, University of Cincinnati
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Ban Takashi
Department Of Pharmacology School Of Medicine Yamaguchi University
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Ban Takashi
Department Of Pharmacology Faculty Of Medicine Kyoto University
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SADA Hideaki
Department of Pharmacology, School of Medicine, Yamaguchi University
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Sada H
Department Of Pharmacology School Of Medicine Yamaguchi University
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Sperelakis N
Univ. Cincinnati Ohio Usa
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Sperelakis Nicholas
Department Of Molecular And Cellular Physiology College Of Medicine University Of Cincinnati
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