BINDING OF TRITIATED DIGOXIN TO HUMAN RED CELL GHOSTS

THE binding of cardiotonic glycosides to (Na+ + K+)-activated ATPase preparations from heart muscle, cat brain and Electrophorus electric organ requires certain specific conditions1,2. 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. © 1969 Nature Publishing Group.