Biomaterial Database

Nanomolar concentrations of ouabain block ethanol-inducible Na+,K(+)-ATPase activity in brain. 1995

T D Foley, and M Linnoila

LCS, DICBR, National Institute on Alcohol Abuse and Alcoholism, NIH, Rockville, MD 20852, USA.

The effect of low concentrations of ethanol on Na+,K(+)-ATPase activity, defined as ouabain-inhibitable 86Rb+ (K+) uptake, was investigated in a crude synaptosome preparation which was subject to minimal subcellular fractionation procedures. Moderate (20-30%) but potent (EC50 = 3.8 mM) stimulation of total ouabain (1 mM)-inhibitable K+ uptake by ethanol was observed following incubation periods of up to 20 min. The activity of the ethanol-induced component of K+ uptake was antagonized by nanomolar concentrations of ouabain. Thus, the moderate stimulation of total ouabain-inhibitable K+ uptake by ethanol was attributable to the activation of a component of K+ uptake which was very sensitive (VS; IC50 = 2.8 x 10(-10) M) to inhibition by ouabain. Slightly higher concentrations of ouabain (10(-9) - 10(-6.6) M) stimulated K+ uptake above control (no ethanol or ouabain) in both the absence and presence of ethanol. The selectivity of the VS-ethanol interaction was demonstrated by the lack of any ethanol effect on two other components of ouabain-inhibitable K+ uptake which accounted for inhibition of K+ uptake by concentrations of ouabain above 10(-6.6) M and were defined as sensitive (S; IC50 = 10(-6) M) and insensitive (I; IC50 = 10(-4) M) to ouabain. These results define the ethanol-inducible component of ouabain-inhibitable Na+,K(+)-ATPase activity and promote the view that changes in Na+,K(+)-ATPase-dependent ion translocation may contribute to ethanol intoxication in vivo.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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.
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D000254	Sodium-Potassium-Exchanging ATPase	An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.	ATPase, Sodium, Potassium,Adenosinetriphosphatase, Sodium, Potassium,Na(+)-K(+)-Exchanging ATPase,Na(+)-K(+)-Transporting ATPase,Potassium Pump,Sodium Pump,Sodium, Potassium ATPase,Sodium, Potassium Adenosinetriphosphatase,Sodium-Potassium Pump,Adenosine Triphosphatase, Sodium, Potassium,Na(+) K(+)-Transporting ATPase,Sodium, Potassium Adenosine Triphosphatase,ATPase Sodium, Potassium,ATPase, Sodium-Potassium-Exchanging,Adenosinetriphosphatase Sodium, Potassium,Pump, Potassium,Pump, Sodium,Pump, Sodium-Potassium,Sodium Potassium Exchanging ATPase,Sodium Potassium Pump
D000431	Ethanol	A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in ALCOHOLIC BEVERAGES.	Alcohol, Ethyl,Absolute Alcohol,Grain Alcohol,Alcohol, Absolute,Alcohol, Grain,Ethyl Alcohol
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
D012414	Rubidium Radioisotopes	Unstable isotopes of rubidium that decay or disintegrate emitting radiation. Rb atoms with atomic weights 79-84, and 86-95 are radioactive rubidium isotopes.	Radioisotopes, Rubidium
D013574	Synaptosomes	Pinched-off nerve endings and their contents of vesicles and cytoplasm together with the attached subsynaptic area of the membrane of the post-synaptic cell. They are largely artificial structures produced by fractionation after selective centrifugation of nervous tissue homogenates.	Synaptosome