title: [Characterization of an endogenous factor with digitalis-like activity in the heart of the guinea pig (I): Inhibition of Na,K-ATPase)].
abstract: The purpose of this work is to study the presence of an endogenous inhibitor of the sodium pump in mammals. A water extract was prepared from guinea pig heart and partially purified by liquid chromatography. The extract inhibited the activity of Na,K-ATPase but had no effect on Mg-ATPase nor on Ca-ATPase. The inhibition was similar to that produced by cardiac glycosides since it was dose-dependent, antagonised by potassium and the Na,K-ATPase prepared from brain was more sensitive than the one from heart. These results support the hypothesis on an endogenous factor exhibiting digitalis-like activity that could be a physiological regulator of the sodium pump.
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000032:analysis*; D001923:Brain Chemistry; D002298:Cardenolides; D004077:Digoxin; D006168:Guinea Pigs; D009206:Myocardium / Q000032:analysis*; D012503:Saponins; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
chemical_list: D001798:Blood Proteins; D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase
vernacular_title: Caracterización de un factor endógeno con actividad digitálica en el corazón de cobayo (I): Inhibición de la Na,K-ATPasa.