Immunocytochemical study of NA+ K(+)-ATPase alpha 1 and beta 1 subunits in human and rat normal hepatocytes using confocal microscopy.

Hepatic Na+ K(+)-ATPase was recently shown to be composed of two alpha 1 and beta 1 subunits similar to that of kidney. Its localization on hepatocyte plasma membranes was not clearly established. We have studied the localization of alpha 1 and beta 1 subunits using immunocytochemical method and confocal microscopy. In accordance with previous cytochemical findings, the catalytic alpha 1 subunit was distributed in basolateral and bile canalicular membranes of hepatocytes. The beta 1 subunit was not demonstrated, due to its very low amount in the liver. The controversy about the bile canalicular localization was discussed.