title: Characterization of ouabain receptor in neuronal tissue: evidence for endogenous ouabain-like compound.
abstract: This study shows that [3H]ouabain binds specifically to a single, saturable binding site located on rat brain membranes with an affinity constant of 6.21 X 10(-8) M. As expected from studies on the mechanics of the Na+,K+-ATPase, sodium increased while potassium and lithium decreased ouabain binding. The occupation of other neurotransmitter receptors did not affect [3H]ouabain binding. Based on its ability to compete with [3H]ouabain binding and to inhibit Na+,K+-ATPase, it is suggested that rat brain extract contains an endogenous ouabain-like compound. The results are discussed with respect to the possibility that the ouabain receptor is a physiological regulatory site of the Na+,K+-ATPase activity.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D017301:Ca(2+) Mg(2+)-ATPase; D066298:In Vitro Techniques; D008094:Lithium / Q000494:pharmacology; D008297:Male; D010042:Ouabain / Q000032:analysis / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011955:Receptors, Drug / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D011955:Receptors, Drug; C028996:cardiac glycoside receptors; D010042:Ouabain; D008094:Lithium; D012964:Sodium; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium