Biomaterial Database

Possible mechanisms underlying the vasodilatation induced by olprinone, a phosphodiesterase III inhibitor, in rabbit coronary artery. 2000

M Ohashi, and Y Dohi, and T Itoh

Department of Pharmacology, Nagoya City University Medical School, Mizuho-Ku, Nagoya 467-8601, Japan.

The possible mechanisms underlying the vasodilatation induced by olprinone, a phosphodiesterase type III inhibitor, were investigated in smooth muscle of the rabbit coronary artery. Isometric force and membrane potential were measured simultaneously using endothelium-denuded smooth muscle strips. Acetylcholine (ACh, 3 microM) produced a contraction with a membrane depolarization (15. 2+/-1.1 mV). In a solution containing 5.9 mM K(+), olprinone (100 microM) hyperpolarized the resting membrane and (i) caused the absolute membrane potential level reached with ACh to be more negative (but did not reduce the delta membrane potential seen with ACh, 15.2+/-1.8 mV) and (ii) attenuated the ACh-induced contraction. In a solution containing 30 mM K(+), these effects were not seen with olprinone. Glibenclamide (10 microM) blocked the olprinone-induced membrane hyperpolarization. 4-AP (0.1 mM) significantly attenuated the olprinone-induced resting membrane hyperpolarization but TEA (1 mM) had no such effect. Glibenclamide (10 +microM), TEA (1 mM) and 4-AP (0.1 mM), given separately, all failed to modify the inhibitory actions of olprinone on (i) the absolute membrane potential level seen with ACh and (ii) the ACh-induced contraction. It is suggested that olprinone inhibits the ACh-induced contraction through an effect on the absolute level of membrane potential achieved with ACh in smooth muscle of the rabbit coronary artery. It is also suggested that glibenclamide-sensitive, ATP-sensitive K(+) channels do not play an important role in the olprinone-induced inhibition of the ACh-induced contraction.

UI	MeSH Term	Description	Entries
D007004	Hypoglycemic Agents	Substances which lower blood glucose levels.	Antidiabetic,Antidiabetic Agent,Antidiabetic Drug,Antidiabetics,Antihyperglycemic,Antihyperglycemic Agent,Hypoglycemic,Hypoglycemic Agent,Hypoglycemic Drug,Antidiabetic Agents,Antidiabetic Drugs,Antihyperglycemic Agents,Antihyperglycemics,Hypoglycemic Drugs,Hypoglycemic Effect,Hypoglycemic Effects,Hypoglycemics,Agent, Antidiabetic,Agent, Antihyperglycemic,Agent, Hypoglycemic,Agents, Antidiabetic,Agents, Antihyperglycemic,Agents, Hypoglycemic,Drug, Antidiabetic,Drug, Hypoglycemic,Drugs, Antidiabetic,Drugs, Hypoglycemic,Effect, Hypoglycemic,Effects, Hypoglycemic
D007093	Imidazoles	Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).
D007537	Isometric Contraction	Muscular contractions characterized by increase in tension without change in length.	Contraction, Isometric,Contractions, Isometric,Isometric Contractions
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D009579	Nitrobenzoates	Benzoic acid or benzoic acid esters substituted with one or more nitro groups.	Nitrobenzoic Acids,Acids, Nitrobenzoic
D010726	Phosphodiesterase Inhibitors	Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.	Phosphodiesterase Antagonists,Phosphodiesterase Inhibitor,Phosphoric Diester Hydrolase Inhibitors,Antiphosphodiesterases,Inhibitor, Phosphodiesterase
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011728	Pyridones	Pyridine derivatives with one or more keto groups on the ring.	Pyridinones