2008 JASN IMPACT FACTOR 7.505	HOME   AUTHOR INFO   EDITORIAL BOARD   SUBSCRIBE   FEEDBACK   ALERTS   HELP
advanced	CURRENT ISSUE	ARCHIVES	JASN Express	ONLINE SUBMISSION

This Article Full Text (Rapid PDF) All Versions of this Article: ASN.2005121381v1 17/6/1657    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Li, C. Articles by Schrier, R. W. Search for Related Content PubMed PubMed Citation Articles by Li, C. Articles by Schrier, R. W.

Received December 30, 2005
Accepted on April 4, 2006

BASIC SCIENCE: Pathophysiology of Renal Disease and Progression

Hyperosmolality In Vivo Upregulates Aquaporin 2 Water Channel and Na-K-2Cl Co-Transporter in Brattleboro Rats

Chunling Li ^*, Weidong Wang ^*, Sandra N. Summer ^*, Melissa A. Cadnapaphornchai ^*, Sandor Falk ^*, Fuminori Umenishi ^*, and Robert W. Schrier ^*1

Departments of *Medicine and Pediatrics, University of Colorado School of Medicine, Denver, Colorado

¹ To whom correspondence should be addressed. E-mail: robert.schrier{at}uchsc.edu.

	Abstract

There are considerable experimental results that indicate that arginine vasopressin (AVP)-independent factors are involved in urinary concentration. This study examined the role of hyperosmolality in vivo to modulate aquaporin 2 (AQP2) and Na-K-2Cl co-transporter (NKCC2), pivotal factors in urinary concentration, in AVP-deficient Brattleboro (BB) rats. Hyperglycemia with associated hyperosmolality occurred in diabetic BB rats (BBDM). Protein abundance of AQP2 increased and was reversed by insulin in the inner medulla (IM; control 100 ± 5%; BBDM 146 ± 8%; BBDM+Ins 122 ± 9%; P < 0.001) and inner stripe of outer medulla (ISOM; control 100 ± 4%; BBDM 123 ± 8%; BBDM+Ins 93 ± 6%; P < 0.05). These results were confirmed by immunohistochemistry studies. NKCC2 rose in the ISOM but was not reversed with insulin treatment. For investigation of the role of hyperosmolality in the absence of hyperglycemia on the regulation of the expression of renal AQP and NKCC2, studies were performed with hyperosmolality that was induced by 0.5% NaCl in drinking water in BB rats. Hyperosmolality that was induced by NaCl increased significantly the protein abundance of IM AQP2 (121 ± 2 versus 100 ± 5%; P < 0.01), ISOM AQP2 (135 ± 6 versus 100 ± 5%; P < 0.001), cortex plus outer stripe of outer medulla AQP2 (121 ± 4 versus 100 ± 1%; P < 0.001), ISOM NKCC2 (133 ± 1 versus 100 ± 4%; P < 0.05), and cortex plus outer stripe of outer medulla NKCC2 (142 ± 16 versus 100 ± 9%; P < 0.05). In conclusion, hyperosmolality, secondary to either glucose or NaCl, upregulated renal AQP2 and NKCC2 in vivo in BB rats.

This article has been cited by other articles:

				M. S. Kwon, S. W. Lim, and H. M. Kwon Hypertonic Stress in the Kidney: A Necessary Evil Physiology, June 1, 2009; 24(3): 186 - 191. [Abstract] [Full Text] [PDF]

				C. Li, W. Wang, S. N. Summer, S. Falk, and R. W. Schrier Downregulation of UT-A1/UT-A3 Is Associated with Urinary Concentrating Defect in Glucocorticoid-Excess State J. Am. Soc. Nephrol., October 1, 2008; 19(10): 1975 - 1981. [Abstract] [Full Text] [PDF]

				P. Welker, A. Bohlick, K. Mutig, M. Salanova, T. Kahl, H. Schluter, D. Blottner, J. Ponce-Coria, G. Gamba, and S. Bachmann Renal Na+-K+-Cl- cotransporter activity and vasopressin-induced trafficking are lipid raft-dependent Am J Physiol Renal Physiol, September 1, 2008; 295(3): F789 - F802. [Abstract] [Full Text] [PDF]

				W. Wang, C. Li, S. N. Summer, S. Falk, W. Wang, D. Ljubanovic, and R. W. Schrier Role of AQP1 in endotoxemia-induced acute kidney injury Am J Physiol Renal Physiol, June 1, 2008; 294(6): F1473 - F1480. [Abstract] [Full Text] [PDF]

				C. Li, W. Wang, S. N. Summer, T. D. Westfall, D. P. Brooks, S. Falk, and R. W. Schrier Molecular Mechanisms of Antidiuretic Effect of Oxytocin J. Am. Soc. Nephrol., February 1, 2008; 19(2): 225 - 232. [Abstract] [Full Text] [PDF]

				Q. Cai, M. R. McReynolds, M. Keck, K. A. Greer, J. B. Hoying, and H. L. Brooks Vasopressin receptor subtype 2 activation increases cell proliferation in the renal medulla of AQP1 null mice Am J Physiol Renal Physiol, December 1, 2007; 293(6): F1858 - F1864. [Abstract] [Full Text] [PDF]

				J. Y. S. Chu, S. C. K. Chung, A. K. M. Lam, S. Tam, S. K. Chung, and B. K. C. Chow Phenotypes Developed in Secretin Receptor-Null Mice Indicated a Role for Secretin in Regulating Renal Water Reabsorption Mol. Cell. Biol., April 1, 2007; 27(7): 2499 - 2511. [Abstract] [Full Text] [PDF]

				V. Bahr, N. Franzen, W. Oelkers, A. F H Pfeiffer, and S. Diederich Effect of exogenous glucocorticoid on osmotically stimulated antidiuretic hormone secretion and on water reabsorption in man Eur. J. Endocrinol., December 1, 2006; 155(6): 845 - 848. [Abstract] [Full Text] [PDF]

				R. W. Schrier Body Water Homeostasis: Clinical Disorders of Urinary Dilution and Concentration J. Am. Soc. Nephrol., July 1, 2006; 17(7): 1820 - 1832. [Full Text] [PDF]

Copyright © 2009 by the American Society of Nephrology. Online ISSN: 1533-3450 Print ISSN: 1046-6673