Some effects of nicorandil on the smooth muscles of the rat and guinea pig

Journal Article · Thu Jan 01 04:00:00 EST 1987 · J. Cardiovasc. Pharmacol.; (United States)

DOI:https://doi.org/10.1097/00005344-198706108-00010· OSTI ID:5481417

Weston, A H

In rat isolated portal vein, nicorandil (0.1-500 microM) abolished spontaneous tension waves and inhibited mechanical responses to norepinephrine (0.1-100 microM) and KCl (5-80 mM). Intracellular electrical recording showed that nicorandil (0.1-1 microM) abolished spontaneous multispike complexes and at higher concentrations (up to 500 microM) raised the membrane potential to approximately -90 mV. Using /sup 86/Rb as a K+-marker, nicorandil (5-500 microM) increased the /sup 86/Rb efflux rate coefficient. In rat isolated aorta, nicorandil (8-32 microM) inhibited mechanical responses to norepinephrine (0.125-100 microM) and KCl (5-80 mM), but had no effect on /sup 86/Rb exchange. In guinea pig isolated taenia caeci, nicorandil (4-64 microM) relaxed spontaneous mechanical tone and increased /sup 86/Rb efflux in the absence and presence of apamin, 100 nM. It is concluded that the inhibitory effects of nicorandil in portal vein and taenia caeci are mediated at least in part by a mechanism which involves the opening of apamin-insensitive, /sup 86/Rb-permeable K+ channels. In aorta, however, the opening of such channels was not detected, and the inhibitory effects of nicorandil in this tissue are associated with an, as yet, undefined mechanism.

• Research Organization: Univ. of Manchester, England
• OSTI ID: 5481417
• Journal Information: J. Cardiovasc. Pharmacol.; (United States), Journal Name: J. Cardiovasc. Pharmacol.; (United States); ISSN JCPCD
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ALKALI METAL ISOTOPES
ALKALI METALS
AMIDES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
DRUGS
ELEMENTS
GUINEA PIGS
HETEROCYCLIC COMPOUNDS
HORMONES
IN VITRO
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEMBRANES
METALS
MINUTES LIVING RADIOISOTOPES
MUSCLES
NEUROREGULATORS
NICOTINAMIDE
NORADRENALINE
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
POTASSIUM
PYRIDINES
RADIOISOTOPES
RATS
RODENTS
RUBIDIUM 86
RUBIDIUM ISOTOPES
STEROID HORMONES
SYMPATHOMIMETICS
TRACER TECHNIQUES
VASOCONSTRICTION
VASODILATORS
VERTEBRATES
VITAMIN B GROUP
VITAMINS