Biomaterial Database

Mechanism of contractile action of barium ion on rat aortic smooth muscle. 1987

A B Ebeigbe, and C P Aloamaka

Department of Physiology, College of Medical Sciences, University of Benin, Nigeria.

The mechanism of Ba2+-induced contraction has been examined in helical strips of Ca2+-depleted, 60 mM K+-depolarized rat aortae. The concentration-response curves to Ca2+ or Ba2+ were significantly potentiated by exposure to 3 X 10(-8) M Bay K 8644 (a Ca2+ channel agonist) in the order Ca2+ greater than Ba2+, suggesting an action of Ba2+ ions through potential-sensitive membrane Ca2+ channels. Exposure of strips to background concentration of Ca2+ (0.05 mM) enhanced the contractile responses to Ba2+, whereas background exposure to Ba2+ (0.1 mM) attenuated Ca2+ responses. Repeated stimulation with Ba2+ resulted in tachyphylaxis, contrary to the result when Ca2+ was used. The results suggest that Ba2+ ions enter rat aortic smooth muscle cells through Ca2+ channels and mobilize a noradrenaline-insensitive intracellular Ca2+ pool. Ba2+ may also cause a desensitization of some intracellular process.

UI	MeSH Term	Description	Entries
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
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D002122	Calcium Chloride	A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.	Calcium Chloride Dihydrate,Calcium Chloride, Anhydrous
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
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
D001012	Aorta, Abdominal	The aorta from the DIAPHRAGM to the bifurcation into the right and left common iliac arteries.	Abdominal Aorta,Abdominal Aortas,Aortas, Abdominal
D001464	Barium	An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.
D013618	Tachyphylaxis	Rapidly decreasing response to a drug or physiologically active agent after administration of a few doses. In immunology, it is the rapid immunization against the effect of toxic doses of an extract or serum by previous injection of small doses. (Dorland, 28th ed)
D017609	Barium Compounds	Inorganic compounds that contain barium as an integral part of the molecule.	Compounds, Barium