[Na, K-ATPase--its structure, gene isoforms, and possible roles in cardiac cells]

A short history of the study of Na, K-ATPase, the Na- and K-transporting enzyme of animal cell membranes, and its present state of investigation are described. Parallelism between the enzyme activity and sodium flux across the cell membrane, subunit constitution and characteristic distribution among different tissues, isoform gene structures and regulation of their specific expression, and especially the inhibition of the enzyme by ouabain are discussed in relation to cardiac functions.