Binding of Tritiated Digoxin to Human Red Cell Ghosts

Abstract

THE binding of cardiotonic glycosides to (Na⁺ + K⁺)-activated ATPase preparations from heart muscle, cat brain and Electrophorus electric organ requires certain specific conditions^1,2. The data are consistent with the same quantitative relationship between glycoside binding, Na⁺-dependent phosphorylation and (Na⁺ + K⁺)-activated ATP hydrolysis in all these tissues, although they differ considerably in their specific activities. Erythrocytes are another tissue from which (Na⁺ + K⁺)-activated ATPase preparations of low specific activity can easily be made, and which can also be used for studies of glycoside binding. Our experiments show that there is a similar binding of specifically labelled digoxin to a red cell ghost preparation.