Characterization of renal Na-K-ATPase gene expression by in situ hybridization

Na-K-ATPase is a heterodimer of alpha- and beta-subunits often referred to as the 'sodium pump' responsible for the maintenance of cell volume and electric potential across cell membranes. In the present study we have used antisense RNA probes to localize these subunits in the rat kidney by in situ hybridization. alpha 1-Subunit and beta-subunit gene expression are highest in cortical distal convoluted tubules, and the thick ascending limb of the loops of Henle; high in some proximal convoluted tubules, and low in the collecting ducts and blood vessels. Expression of the alpha 11 and alpha 111 isoforms is very low or absent throughout the kidney. These results confirm and extend studies of Na-K-ATPase enzyme activity levels and immunocytochemical localization in the kidney.