title: Digitalis-like factors from human urine.
abstract: We isolated two candidates for endogenous digitalis-like factors from human urine based on the inhibition of [3H]ouabain binding to intact human erythrocytes. The more-polar ouabain-displacing compound-1 (ODC-1) closely resembled ouabain in biological, physicochemical, and chromatographic properties. Moreover, anti-ouabain IgG dose-dependently neutralized the action of ODC-1. The less-polar ODC-2 behaved identically to digoxin in three analytical high-performance liquid chromatography and thin layer chromatography systems. Fast atom bombardment mass spectrum and proton nuclear magnetic resonance spectrum supported the notion that ODC-2 may be indistinguishable from digoxin. The possibility that substances quite similar to cardenolides are synthesized in the mammalian body must be seriously considered.
authors.affiliation: Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Goto
authors.forename: K
authors.initials: K
authors.lastname: Yamada
authors.forename: N
authors.initials: N
authors.lastname: Yagi
authors.forename: C
authors.initials: C
authors.lastname: Hui
authors.forename: H
authors.initials: H
authors.lastname: Nagoshi
authors.forename: M
authors.initials: M
authors.lastname: Sasabe
authors.forename: M
authors.initials: M
authors.lastname: Yoshioka
mesh_terms: D001665:Binding Sites; D001685:Biological Factors / Q000737:chemistry / Q000302:isolation & purification / Q000652:urine*; D001798:Blood Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000652:urine*; D002298:Cardenolides; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004077:Digoxin; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010042:Ouabain / Q000378:metabolism; D012503:Saponins; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
chemical_list: D001685:Biological Factors; D001798:Blood Proteins; D002298:Cardenolides; D007074:Immunoglobulin G; D012503:Saponins; C034504:digoxin-like factors; D010042:Ouabain; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase