[Physiological functions of (Na+ + K+)-adenosinetriphosphatase (ATPase) isozymes]

Since Sweadner demonstrated that there are two isozymes (alpha and alpha(+) isoforms) of (Na+ + K+)-adenosine triphosphatase (ATPase) in the brain about 10 years ago, the isozymes have been extensively studied at biochemical and molecular levels. We started the studies on the isozymes of (Na+ + K+)-ATPase soon after finding that pyrithiamin, an antimetabolite of thiamin is a selective inhibitor of the alpha(+)isoform. This review summarizes the previous studies on the isozymes of (Na+ + K+)-ATPase, which are now classified into alpha 1, alpha 2, and alpha 3.