1. Developmental changes in action potential prolongation by K+-channel blockers in chick myocardium.
- Author
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Nouchi H, Kiryu N, Kimata M, Tsuneoka Y, Hamaguchi S, Namekata I, Takahara A, Shigenobu K, and Tanaka H
- Subjects
- Animals, Arrhythmias, Cardiac chemically induced, Arrhythmias, Cardiac physiopathology, Chick Embryo, Delayed Rectifier Potassium Channels metabolism, Drug Evaluation, Preclinical, Long QT Syndrome chemically induced, Long QT Syndrome physiopathology, Action Potentials drug effects, Delayed Rectifier Potassium Channels antagonists & inhibitors, Heart Ventricles drug effects, Myocardium metabolism, Potassium Channel Blockers pharmacology, Potassium Channels metabolism
- Abstract
The effects of K(+)-channel blockers on the action potential duration of the myocardium were examined in isolated right ventricles from the 7 - 10-day-old, 11 - 13-day-old, and 14 - 20-day-old embryo and 1 - 7-day-old hatched chicks. E-4031 significantly prolonged action potential duration at all developmental stages examined; the prolongation was largest in the 11 - 13-day-old embryo and was accompanied by early after-depolarizations. Chromanol 293B showed smaller prolongation at all stages examined. Terfenadine prolonged action potential duration in the 11 - 13-day-old embryo, but not in other stages. Thus, the chick ventricular myocardium changes its repolarization properties during development.
- Published
- 2011
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