Digitalis-Like Compounds in Animal Tissues

The Na+, K+ activated adenosine triphosphatase is present in the membrane of eukaryotic cells and represents a major pathway for Na+ and K+ transport across the plasma membrane. Cardiac glycosides such as ouabain or digoxin suppress this enzyme activity by binding to a specific receptor on the membrane. Studies conducted in this and other laboratories have proven the existence of digitalis-like compounds in animal tissues which may serve as in vivo regulators of the Na+, K(+)-pump activity. This review summarizes the attempts to identify these compounds from animal tissues and examines the potential physiological role of some of the identified compounds.