Expression and molecular regulation of Na(+)-K(+)-ATPase after renal ischemia. Am J Physiol 1994 Jul;267(1 Pt 2):F75-85
Date
07/01/1994Pubmed ID
8048568DOI
10.1152/ajprenal.1994.267.1.F75Scopus ID
2-s2.0-0027990439 (requires institutional sign-in at Scopus site) 59 CitationsAbstract
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.
Author List
Van Why SK, Mann AS, Ardito T, Siegel NJ, Kashgarian MAuthor
Scott K. Van Why MD Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBlotting, Northern
Blotting, Western
Cell Polarity
Immunohistochemistry
Ischemia
Male
Microscopy, Electron
Protein Processing, Post-Translational
RNA, Messenger
Rats
Rats, Sprague-Dawley
Renal Circulation
Reperfusion
Sodium-Potassium-Exchanging ATPase
Transcription, Genetic