HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 293/1/F87    most recent 00431.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by de Seigneux, S. Articles by Nielsen, S. Search for Related Content PubMed PubMed Citation Articles by de Seigneux, S. Articles by Nielsen, S.

Long-term aldosterone treatment induces decreased apical but increased basolateral expression of AQP2 in CCD of rat kidney

¹The Water and Salt Research Center and ²Institute of Anatomy, University of Aarhus, Aarhus C; ³Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea; and ⁴Institute of Clinical Medicine, Aarhus University Hospital, Aarhus N, Denmark

Submitted 30 October 2006 ; accepted in final form 16 March 2007

The purpose of the present studies was to determine the effects of high-dose aldosterone and dDAVP treatment on renal aquaporin-2 (AQP2) regulation and urinary concentration. Rats were treated for 6 days with either vehicle (CON; n = 8), dDAVP (0.5 ng/h, dDAVP, n = 10), aldosterone (Aldo, 150 µg/day, n = 10) or combined dDAVP and aldosterone treatment (dDAVP+Aldo, n = 10) and had free access to water with a fixed food intake. Aldosterone treatment induced hypokalemia, decreased urine osmolality, and increased the urine volume and water intake in ALDO compared with CON and dDAVP+Aldo compared with dDAVP. Immunohistochemistry and semiquantitative laser confocal microscopy revealed a distinct increase in basolateral domain AQP2 labeling in cortical collecting duct (CCD) principal cells and a reduction in apical domain labeling in Aldo compared with CON rats. Given the presence of hypokalemia in aldosterone-treated rats, we studied dietary-induced hypokalemia in rats, which also reduced apical AQP2 expression in the CCD but did not induce any increase in basolateral AQP2 expression in the CCD as observed with aldosterone treatment. The aldosterone-induced basolateral AQP2 expression in the CCD was thus independent of hypokalemia but was dependent on the presence of sodium and aldosterone. This redistribution was clearly blocked by mineralocorticoid receptor blockade. The increased basolateral expression of AQP2 induced by aldosterone may play a significant role in water metabolism in conditions with increased sodium reabsorption in the CCD.

aquaporin-2; mineralocorticoid; water; salt; trafficking; cortical collecting duct

This article has been cited by other articles:

				B. Edemir, S. Reuter, R. Borgulya, R. Schroter, U. Neugebauer, G. Gabriels, and E. Schlatter Acute Rejection Modulates Gene Expression in the Collecting Duct J. Am. Soc. Nephrol., March 1, 2008; 19(3): 538 - 546. [Abstract] [Full Text] [PDF]

				Y. H. Kim, V. Pech, K. B. Spencer, W. H. Beierwaltes, L. A. Everett, E. D. Green, W. Shin, J. W. Verlander, R. L. Sutliff, and S. M. Wall Reduced ENaC protein abundance contributes to the lower blood pressure observed in pendrin-null mice Am J Physiol Renal Physiol, October 1, 2007; 293(4): F1314 - F1324. [Abstract] [Full Text] [PDF]