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Block of outward current in cardiac purkinje fibers by injection of quaternary ammonium ions

We have studied the effects of iontophoretic injection of the quaternary ammonium compounds tetraethylammonium (TEA) and tetrabutylammonium (TBA) in cardiac purkinje fibers. We find that TBA(+) is a more effective blocker than TEA(+), but injection of either compound reduces the time-dependent outwa...

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Detalles Bibliográficos
Autores principales: Kass, RS, Scheuer, T, Malloy, KJ
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1982
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2216454/
https://www.ncbi.nlm.nih.gov/pubmed/6286842
Descripción
Sumario:We have studied the effects of iontophoretic injection of the quaternary ammonium compounds tetraethylammonium (TEA) and tetrabutylammonium (TBA) in cardiac purkinje fibers. We find that TBA(+) is a more effective blocker than TEA(+), but injection of either compound reduces the time-dependent outward plateau currents, transient outward current (I(to)), and the delayed rectifier (I(x)). Our findings provide evidence that these outward cardiac currents are carried by channels that in some respects are pharmacologically similar to squid axon potassium channels. We demonstrate that this procedure is a new tool that can be useful in the analysis of membrane currents in the heart.