title: Endogenous "ouabain-like" activity in bovine plasma.
abstract: An endogenous inhibitor of the sodium pump has been detected and concentrated 1000-fold from bovine plasma. The steps of purification included deproteinization and extraction with methanol, removal of lipids by coextractions with a lipophilic solvent, desalting and further concentration by adsorption on C18-SepPack cartridges and HPLC fractionation on a weak anionic exchange column. The material isolated displaces 3H-ouabain from brain synaptosomes, inhibits red cell membrane Na,K-ATPase without inhibiting Mg-ATPase or Ca,Mg-ATPase. Deproteinization of plasma by boiling may lead to appearance of non-specific inhibitors. The procedures developed should now permit isolation of sufficient amount of material for further purification and structural characterization.
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000097:blood*; D004910:Erythrocyte Membrane / Q000201:enzymology; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase