Pflügers Archiv

, Volume 329, Issue 3, pp 191–206

The localization of the Na+−K+-ATPase in the cells of rat kidney cortex

A study on isolated plasma membranes
  • Rolf Kinne
  • Jürgen-Erik Schmitz
  • Evamaria Kinne-Saffran
Article

DOI: 10.1007/BF00586614

Cite this article as:
Kinne, R., Schmitz, JE. & Kinne-Saffran, E. Pflugers Arch. (1971) 329: 191. doi:10.1007/BF00586614

Summary

Plasma membrane fractions of rat kidney cortex were subdivided by centrifugation on a continuous and a discontinuous sucrose gradient and by carrier free continuous electrophoresis. In the different fractions the activity of alkaline phosphatase and aminopeptidase, enzymes which are present in the brushborder membrane, as well as Mg++-ATPase, Na+−K+-ATPase, 5′-nucleotidase, acid phosphatase and glucose-6-phosphatase were determined.

The distribution of alkaline phosphatase, aminopeptidase and 5′-nucleotidase is identical, indicating the localization of these enzymes in the brushborder membrane. Na+−K+-ATPase does not show an identical distribution with any of the enzymes studied.

Using carrier free continuous electrophoresis fractions can be obtained which are enriched in alkaline phosphatase by a factor of 15 when compared to the cortex homogenate, whereas the specific activity of Na+−K+-ATPase is reduced to one third of the starting material. On the other hand fractions can be isolated in which the specific activity of Na+−K+-ATPase is 16 times higher than in the homogenate. No enrichment of alkaline phosphatase occurs in these fractions.

It is therefore concluded that the Na+−K+-ATPase is not present in the brushborder membrane nor in the lysosomes or endoplasmatic reticulum. The most probable localization of the Na+−K+-ATPase are the basal infoldings of the plasma membranes of the cells.

Key-Words

Rat Kidney Plasma Membranes Brushborder Basal Infoldings Mg++−Na+−K+-ATPase Transepithelial Sodium Transport 

Copyright information

© Springer-Verlag 1971

Authors and Affiliations

  • Rolf Kinne
    • 1
  • Jürgen-Erik Schmitz
    • 1
  • Evamaria Kinne-Saffran
    • 1
  1. 1.Max-Planck-Institut für BiophysikFrankfurt am MainGermany

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