Expression and molecular regulation of Na(+)-K(+)-ATPase after renal ischemia

Am J Physiol. 1994 Jul;267(1 Pt 2):F75-85. doi: 10.1152/ajprenal.1994.267.1.F75.


Renal ischemia causes redistribution of Na(+)-K(+)-adenosinetriphosphatase (Na(+)-K(+)-ATPase) to the apical membrane of proximal tubules. We determined the time course of regeneration of Na(+)-K(+)-ATPase polarity and sought evidence of increased enzyme production during recovery as a means to restore polarity. Anesthetized rats underwent 45 min renal ischemia and reflow of 15 min, 2 h, 6 h, and 24 h. Immunofluorescent and electron microscopy showed loss of strict basolateral localization of Na(+)-K(+)-ATPase at 15 min reflow with repolarization by 24 h in sublethally injured cells. Both alpha 1- and beta-subunits were only in microsomal fractions at all reflow intervals. Immunodetectable levels of both subunits declined to 60-70% of control by 24 h reflow. Levels of mRNA for each subunit declined in parallel through 24 h to 55% of control. Overall transcription was profoundly depressed through 6 h but had recovered to near control by 24 h. Specific transcription of alpha 1- and beta-subunit mRNA was markedly decreased after ischemia and only partially recovered by 24 h. These results suggest that recycling of misplaced units rather than new Na(+)-K(+)-ATPase production is the means by which renal epithelia initially repolarize after ischemic injury.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Northern
  • Blotting, Western
  • Cell Polarity
  • Immunohistochemistry
  • Ischemia / metabolism*
  • Ischemia / pathology
  • Male
  • Microscopy, Electron
  • Protein Processing, Post-Translational
  • RNA, Messenger
  • Rats
  • Rats, Sprague-Dawley
  • Renal Circulation*
  • Reperfusion
  • Sodium-Potassium-Exchanging ATPase / genetics*
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Transcription, Genetic


  • RNA, Messenger
  • Sodium-Potassium-Exchanging ATPase