Blockage of the fast sodium current by dimetindene in frog auricular fibres

J. Meszaros, R. Marko, K. Kelemen, V. Kecskeméti

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The effect of dimetindene (DMI) on action potential and fast inward Na current (I(Na)) of frog atrial fibres was studied using double sucrose gap voltage-clamp technique. DMI reduced the amplitude and maximum rate of rise of the action potentials without altering the resting membrane potential. The drug inhibited the fast Na conductance in a concentration-dependent manner, without changing the reversal potential. The shape of the current-voltage curve along the voltage axis remained unchanged in the presence of DMI. The time to peak of the I(Na) was not significantly altered by the drug whereas the rate of the I(Na) inactivation (τ(h)) was slowed. DMI shifted the steady-state inactivation curve of I(Na) (h(∞)) to more negative potentials, and increased the reactivation time constant of the sodium system (τ(r)). The inhibition of I(Na) was use-dependent. The results suggest that DMI interacts with the inactivation mechanism of the sodium channel of the frog myocardium, and explain its favourable antiarrhythmic activity.

Original languageEnglish
Pages (from-to)321-325
Number of pages5
JournalNaunyn-Schmiedeberg's Archives of Pharmacology
Volume335
Issue number3
Publication statusPublished - 1987

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Dimethindene
Anura
Sodium
Action Potentials
Sodium Channels
Patch-Clamp Techniques
Pharmaceutical Preparations
Membrane Potentials
Sucrose
Myocardium

ASJC Scopus subject areas

  • Pharmacology

Cite this

Blockage of the fast sodium current by dimetindene in frog auricular fibres. / Meszaros, J.; Marko, R.; Kelemen, K.; Kecskeméti, V.

In: Naunyn-Schmiedeberg's Archives of Pharmacology, Vol. 335, No. 3, 1987, p. 321-325.

Research output: Contribution to journalArticle

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