[Ultrastructural localization of adenosine triphosphatase activity in the proximal kidney tubules of white rats].

In white rats, the ferment topography of Mg+2 and (Na+ + K+)-activated ATPh-ses in proximal canaliculi was studied with the aid of the ultrastructural cytochemistry. The final product of the fermentative reaction (PhHPO4) in the form of small dense granuli is positioned on the duplicate folds of epithelial cells, the cells limiting the brush border micropiles, and on invaginations of the apical plasmalemme at the micropiles base. For (Na+ %K+)-activated ATPh-ses a localisation of the reaction product was determined in the canaliculi vessels.