Biomaterial Database

Effects of the Na ionophore monensin on the contractile response and the movements of monovalent cations in the vascular smooth muscle of rabbit aorta. 1982

H Ozaki, and T Kishimoto, and H Karaki, and N Urakawa

The effects of monensin, a Na ionophore, on the muscle contraction and the movements of monovalent cations were investigated in rabbit aorta. Experiments were conducted in the presence of phentolamine (10(-6) M) to avoid the vasoactive effect of monensin due to the release of endogenous catecholamine. Both monensin (2 X 10(-5) M) and ouabain (2 X 10(-5) M), added separately, produced a small and slowly developing contraction, whereas simultaneous application of these agents produced more rapid and greater contraction. Verapamil (10(-6) M) decreased the contraction by 75%. Ouabain gradually increased cellular Na content. Monensin augmented the ouabain-induced Na increase. Further, the loss of cellular Na into Na deficient solution was enhanced by monensin. Low temperature (0.5 degrees C) inhibited the monensin-induced increase in Na permeability. The relaxation of noradrenaline-contraction induced by a K-readmission was inhibited by ouabain but not by monensin. These results suggest that monensin increases Na movement down its electrochemical gradient, augments cellular Na accumulation when the Na pump is inhibited by ouabain, and induces muscle contraction, and that the contraction induced by monensin and ouabain is mainly due to an increased Ca influx through voltage sensitive Ca channels.

UI	MeSH Term	Description	Entries
D008094	Lithium	An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.	Lithium-7,Lithium 7
D008985	Monensin	An antiprotozoal agent produced by Streptomyces cinnamonensis. It exerts its effect during the development of first-generation trophozoites into first-generation schizonts within the intestinal epithelial cells. It does not interfere with hosts' development of acquired immunity to the majority of coccidial species. Monensin is a sodium and proton selective ionophore and is widely used as such in biochemical studies.	Coban,Monensin Monosodium Salt,Monensin Sodium,Monensin-A-Sodium Complex,Rumensin,Monensin A Sodium Complex
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
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
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
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.
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D002414	Cations, Monovalent	Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.	Monovalent Cation,Cation, Monovalent,Monovalent Cations
D005663	Furans	Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.	Tetrahydrofurans
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia