Specific Antagonism by Glibenclamide of Negative Inotropic Effects of Potassium Channel Openers in Canine Atrial Muscle

Eisaku Satoh, Teruyuki Yanagisawa, Norio Taira

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)

Abstract

The mode of antagonism by glibenclamide, a potassium channel blocker, of the negative inotropic effects of potassium channel openers, cromakalim, pinacidil and nicorandil, was investigated in canine atrial muscle. Glibenclamide shifted the concentration-negative inotropic effect curves for cromakalim, pinacidil and nicorandil to the right without affecting the basal force of contraction. Schild analysis yielded uniform pA2 values of 6.06-6.35 for glibenclamide against the three potassium channel openers. The force of contraction of atrial muscles previously reduced by cromakalim was also antagonized by increasing concentrations of glibenclamide. Glibenclamide affected neither the concentratiorvnegative inotropic effect curves for carbachol, an opener of the muscarinic receptor-coupled potassium channel, nor those for nifedipine, a calcium channel blocker. From these results, it became evident that glibenclamide behaved as a pharmacological antagonist of cromakalim, pinacidil and nicorandil in cardiac inotropy. The antagonism seems to involve competition of glibenclamide and these potassium channel openers, presumably at the ATP-sensitive channel in canine right atrial muscles.

Original languageEnglish
Pages (from-to)133-141
Number of pages9
JournalJapanese Journal of Pharmacology
Volume54
Issue number2
DOIs
Publication statusPublished - 1990

ASJC Scopus subject areas

  • Pharmacology

Fingerprint Dive into the research topics of 'Specific Antagonism by Glibenclamide of Negative Inotropic Effects of Potassium Channel Openers in Canine Atrial Muscle'. Together they form a unique fingerprint.

Cite this