Interactions of aminopyridines with potassium channels of squid axon membranes

J. Z. Yeh, G. S. Oxford, C. H. Wu, T. Narahashi

Research output: Contribution to journalArticle

165 Citations (Scopus)

Abstract

The effects of aminopyridines on ionic conductances of the squid giant axon membrane were examined using voltage clamp and internal perfusion techniques. 4 Aminopyridine (4 AP) reduced potassium currents, but had no effect upon transient sodium currents. The block of potassium channels by 4 AP was substantially less with (a) strong depolarization to positive membrane potentials, (b) increasing the duration of a given depolarizing step, and (c) increasing the frequency of step depolarizations. Experiments with high external potassium concentrations revealed that the effects of 4 AP was independent of the direction of potassium ion movement. Both 3 and 2 aminopyridine were distinguishable from 4 AP except in potency. It is concluded that aminopyridines may be used as tools to block the potassium conductance in excitable membranes, but only within certain specific voltage and frequency limits.

Original languageEnglish (US)
Pages (from-to)77-81
Number of pages5
JournalBiophysical Journal
Volume16
Issue number1
StatePublished - 1976
Externally publishedYes

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Aminopyridines
Decapodiformes
4-Aminopyridine
Potassium Channels
Axons
Potassium
Membranes
Membrane Potentials
Perfusion
Sodium
Ions

ASJC Scopus subject areas

  • Biophysics

Cite this

Yeh, J. Z., Oxford, G. S., Wu, C. H., & Narahashi, T. (1976). Interactions of aminopyridines with potassium channels of squid axon membranes. Biophysical Journal, 16(1), 77-81.

Interactions of aminopyridines with potassium channels of squid axon membranes. / Yeh, J. Z.; Oxford, G. S.; Wu, C. H.; Narahashi, T.

In: Biophysical Journal, Vol. 16, No. 1, 1976, p. 77-81.

Research output: Contribution to journalArticle

Yeh, JZ, Oxford, GS, Wu, CH & Narahashi, T 1976, 'Interactions of aminopyridines with potassium channels of squid axon membranes', Biophysical Journal, vol. 16, no. 1, pp. 77-81.
Yeh, J. Z. ; Oxford, G. S. ; Wu, C. H. ; Narahashi, T. / Interactions of aminopyridines with potassium channels of squid axon membranes. In: Biophysical Journal. 1976 ; Vol. 16, No. 1. pp. 77-81.
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