Selective Inhibition by Ethylisopropylamiloride of the Positive Inotropic Effect Evoked by Low Concentrations of Ouabain in Rat Isolated Ventricles

Overview

Journal Br J Pharmacol

Publisher Wiley

Specialty Pharmacology

Date 1986 Nov 1

PMID 2432982

Citations 2

Authors

M Finet

T GODFRAIND

Affiliations

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Abstract

The biphasic positive inotropic effect of ouabain has been studied in rat ventricular strips in the presence of ethylisopropylamiloride (EIPA) an inhibitor of Na+/H+ exchange. EIPA (10-20 microM) depressed dose-dependently the high affinity component of the ouabain inotropic effect, whereas it did not significantly modify the low affinity inotropic effect related to high concentrations of ouabain. At the EIPA concentrations studied, there was no observable modification of the inotropic effect of Bay K 8644 (10 nM, 0.3 microM) or of isoprenaline (10 nM, 1 microM). These results indicate that the inotropic effect of ouabain resulting from its interaction with high affinity sites is selectively sensitive to EIPA.

Citing Articles

Comparison between the cardiac effects induced by muzolimine and furosemide in guinea-pig atria.

Dorigo P, Gaion R, Bergamin M, Giacometti A, Valentini E, Maragno I Cardiovasc Drugs Ther. 1990; 4(6):1477-85.

PMID: 1706935 DOI: 10.1007/BF02026495.

Role of Na-H exchange in the inotropic action of Bay K 8644 and of ouabain in guinea-pig isolated atria.

GODFRAIND T Br J Pharmacol. 1990; 100(4):717-22.

PMID: 1698497 PMC: 1917576. DOI: 10.1111/j.1476-5381.1990.tb14081.x.

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