Effects of nicorandil on electromechanical activity of frog atrial muscle

Mami Noda, Ikunobu Muramatsu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The effects of the antianginal drug nicorandil on electrical and mechanical activity of bullfrog atria were examined. The application of nicorandil at concentrations from 0.3 to 10m M caused a negative inotropic effect without any appreciable change in the resting membrane potential. The amplitude of action potentials was attenuated. In the voltage clamp experiments, the slow inward current was slightly inhibited, but the background inward current and delayed outward current were not affected in the presence of nicorandil. The inward rectifying properties of time-independent outward current were slightly inhibited by 10m M nicorandil. Nicorandil inhibited the caffeine-induced contractures elicited in the depolarized preparation, but had no effect on the contracture mediated through the Na-Ca exchange mechanism. These results suggest that the negative inotropic action of nicorandil is caused by inhibition of Ca influx and intracellular mobilization of Ca. Nicorandil had little effect on the potassium conductance in this preparation.

Original languageEnglish
Pages (from-to)237-241
Number of pages5
JournalJournal of Cardiovascular Pharmacology
Volume9
Issue number2
DOIs
Publication statusPublished - Jan 1 1987
Externally publishedYes

Fingerprint

Nicorandil
Anura
Muscles
Contracture
Rana catesbeiana
Caffeine
Membrane Potentials
Action Potentials
Potassium

All Science Journal Classification (ASJC) codes

  • Pharmacology
  • Cardiology and Cardiovascular Medicine

Cite this

Effects of nicorandil on electromechanical activity of frog atrial muscle. / Noda, Mami; Muramatsu, Ikunobu.

In: Journal of Cardiovascular Pharmacology, Vol. 9, No. 2, 01.01.1987, p. 237-241.

Research output: Contribution to journalArticle

@article{abc2298f37fd4ff3b1bf61bbede5a8d5,
title = "Effects of nicorandil on electromechanical activity of frog atrial muscle",
abstract = "The effects of the antianginal drug nicorandil on electrical and mechanical activity of bullfrog atria were examined. The application of nicorandil at concentrations from 0.3 to 10m M caused a negative inotropic effect without any appreciable change in the resting membrane potential. The amplitude of action potentials was attenuated. In the voltage clamp experiments, the slow inward current was slightly inhibited, but the background inward current and delayed outward current were not affected in the presence of nicorandil. The inward rectifying properties of time-independent outward current were slightly inhibited by 10m M nicorandil. Nicorandil inhibited the caffeine-induced contractures elicited in the depolarized preparation, but had no effect on the contracture mediated through the Na-Ca exchange mechanism. These results suggest that the negative inotropic action of nicorandil is caused by inhibition of Ca influx and intracellular mobilization of Ca. Nicorandil had little effect on the potassium conductance in this preparation.",
author = "Mami Noda and Ikunobu Muramatsu",
year = "1987",
month = "1",
day = "1",
doi = "10.1097/00005344-198702000-00018",
language = "English",
volume = "9",
pages = "237--241",
journal = "Journal of Cardiovascular Pharmacology",
issn = "0160-2446",
publisher = "Lippincott Williams and Wilkins",
number = "2",

}

TY - JOUR

T1 - Effects of nicorandil on electromechanical activity of frog atrial muscle

AU - Noda, Mami

AU - Muramatsu, Ikunobu

PY - 1987/1/1

Y1 - 1987/1/1

N2 - The effects of the antianginal drug nicorandil on electrical and mechanical activity of bullfrog atria were examined. The application of nicorandil at concentrations from 0.3 to 10m M caused a negative inotropic effect without any appreciable change in the resting membrane potential. The amplitude of action potentials was attenuated. In the voltage clamp experiments, the slow inward current was slightly inhibited, but the background inward current and delayed outward current were not affected in the presence of nicorandil. The inward rectifying properties of time-independent outward current were slightly inhibited by 10m M nicorandil. Nicorandil inhibited the caffeine-induced contractures elicited in the depolarized preparation, but had no effect on the contracture mediated through the Na-Ca exchange mechanism. These results suggest that the negative inotropic action of nicorandil is caused by inhibition of Ca influx and intracellular mobilization of Ca. Nicorandil had little effect on the potassium conductance in this preparation.

AB - The effects of the antianginal drug nicorandil on electrical and mechanical activity of bullfrog atria were examined. The application of nicorandil at concentrations from 0.3 to 10m M caused a negative inotropic effect without any appreciable change in the resting membrane potential. The amplitude of action potentials was attenuated. In the voltage clamp experiments, the slow inward current was slightly inhibited, but the background inward current and delayed outward current were not affected in the presence of nicorandil. The inward rectifying properties of time-independent outward current were slightly inhibited by 10m M nicorandil. Nicorandil inhibited the caffeine-induced contractures elicited in the depolarized preparation, but had no effect on the contracture mediated through the Na-Ca exchange mechanism. These results suggest that the negative inotropic action of nicorandil is caused by inhibition of Ca influx and intracellular mobilization of Ca. Nicorandil had little effect on the potassium conductance in this preparation.

UR - http://www.scopus.com/inward/record.url?scp=0023088954&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023088954&partnerID=8YFLogxK

U2 - 10.1097/00005344-198702000-00018

DO - 10.1097/00005344-198702000-00018

M3 - Article

C2 - 2436005

AN - SCOPUS:0023088954

VL - 9

SP - 237

EP - 241

JO - Journal of Cardiovascular Pharmacology

JF - Journal of Cardiovascular Pharmacology

SN - 0160-2446

IS - 2

ER -