Effects of Dofetilide on Membrane Currents in Sinoatrial Node Cells of Rabbit
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概要
- 論文の詳細を見る
The effects of dofetilide (UK 68798) on membrane currents were examined in isolated sinoatrial node cells of rabbits by using patch clamping. At a concentration of 1 pM, dofetilide decreased the delayed rectifier K<SUP>+</SUP> current (I<SUB>K</SUB>) (50.2±10.2%, mean±S.E.). The Ca<SUP>2+</SUP> current was slightly decreased during the application of dofetilide. However, the decrease in the current may be attributed to the “run down” phenomenon. The drug did not affect the hyperpolarization-activated inward current. Therefore, dofetilide exhibited class III antiarrhythmic activity in rabbit sinoatrial node cells. Similarly, E-4031 (1-[2-(6-methyl-2-pyridyl)ethyl]-4-(4-methylsulfonylaminobenzoyl)pireridine) (1 μM), a standard class III agent, also showed specific inhibition of I<SUB>K</SUB>. Furthermore, dofetilide depolarized the maximum diastolic potentials, reduced the slope of the pacemaker potential and then abolished spontaneously firing action potentials in the nodal cells. The results demonstrate that dofetilide may produce negative chronotropic effects as a result of its class III activity.
- 社団法人 日本薬理学会の論文
- 1995-12-01
著者
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Tohse Noritsugu
Department Of Cellular Physiology And Signal Transduction Sapporo Medical University School Of Medic
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Tohse Noritsugu
北海道大学 薬理
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KANNO Morio
Department of Pharmacology, Hokkaido University School of Medicine
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Kanno Morio
Department Of Pharmacology Hokkaido University School Of Medicine
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Tohse Noritsugu
Department Of Pharmacology Hokkaido University School Of Medicine
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