IMMUNOFLUORESCENT LOCALIZATION OF 3 NA,K-ATPASE ISOZYMES IN THE RAT CENTRAL-NERVOUS-SYSTEM - BOTH NEURONS AND GLIA CAN EXPRESS MORE THAN ONE NA,K-ATPASE

In the CNS, there are multiple isozymes of the sodium and potassium ion-stimulated adenosine triphosphatase (Na,K-ATPase) that have differences in affinity for Na+, ATP, and cardiac glycosides. Three forms of the catalytic subunit (designated alpha-1, alpha-2, and alpha-3) are known to be derived from different genes, but little is known of the cellular distributions of the proteins or their physiological roles. Isozyme-specific monoclonal antibodies permitted the immunofluorescent localization of the 3 Na,K-ATPase in the rat CNS, and markedly different patterns of staining were seen. All 3 isozymes were detected, singly or in combination, in 1 or more neuronal structures, while both alpha-1 and alpha-2 were detected in glia. Many different neuroanatomic structures or cell types stained for more than 1 isozyme. Even when a structure or region stained for more than 1 isozyme, the pattern of staining was frequently dissimilar, suggesting complex differences in gene expression and cellular localization.