Cell-Specific Expression of mRNAs Encoding Na+, K+-ATPase α- and β-Subunit Isoforms within the Rat Central Nervous System

We have used in situ hybridization histochemistry to analyze the subcellular distribution of mRNAs encoding Na,K-ATPase α- and β-subunit isoforms in the rat central nervous system. Substantial differences in the cell-specific pattern of expression were found for the genes encoding three isoforms of the α subunit. Transcripts of α1-subunit gene were detected in virtually all cell types and structures examined. Expression of α2-subunit mRNA was characteristic of glia, whereas α3-subunit transcripts were predominant in neurons. Transcripts encoding the β1 subunit were detected in neurons, whereas β2-subunit mRNA expression was characteristic of glia. mRNA encoding both β-subunit isoforms was present in choroidal epithelial cells. The distribution pattern of α- and β-subunit mRNAs in structures throughout the central nervous system is consistent with the possibility of six structurally distinct Na+,K+-ATPase isoenzymes.