2007 JASN IMPACT FACTOR 7.111	HOME   AUTHOR INFO   EDITORIAL BOARD   SUBSCRIBE   FEEDBACK   ALERTS   HELP
advanced	CURRENT ISSUE	ARCHIVES	JASN Express	ONLINE SUBMISSION

This Article Full Text Full Text (PDF) 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 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 Liu, R. Articles by Persson, A. E. G. Search for Related Content PubMed PubMed Citation Articles by Liu, R. Articles by Persson, A. E. G.

Purinergic Receptor Signaling at the Basolateral Membrane of Macula Densa Cells

Ruisheng Liu^*, P. Darwin Bell, Janos Peti-Peterdi, Gergly Kovacs, Alf Johansson^* and A. Erik G. Persson^*

*Department of Physiology, Uppsala University, Uppsala, Sweden; and Division of Nephrology, Nephrology Research and Training Center, and Departments of Medicine and Physiology, University of Alabama at Birmingham, Birmingham, Alabama.

Correspondence to: Dr. A. Erik G. Persson, Department of Physiology, Biomedical Center, Box 572, S-75123, Uppsala, Sweden. Phone: +46-18-4714180; Fax: +46-18-4714938; E-mail: erik.persson{at}physiology.uu.se

ABSTRACT. Purinergic receptors are important in the regulation of renal hemodynamics; therefore, this study sought to determine if such receptors influence macula densa cell function. Isolated glomeruli containing macula densa cells, with and without the cortical thick ascending limb, were loaded with the Ca²⁺ sensitive indicators, Fura Red (confocal microscopy) or fura 2 (conventional video image analysis). Studies were performed on an inverted microscope in a chamber with a flow-through perfusion system. Changes in cytosolic calcium concentration ([Ca²⁺]_i) from exposed macula densa plaques were assessed upon addition of adenosine, ATP, UTP, ADP, or 2-methylthio-ATP (2- MeS-ATP) for 2 min added to the bathing solution. There was no change in [Ca²⁺]_i with addition of adenosine (10^-7 to 10^-3 M). UTP and ATP (10^-4 M) caused [Ca²⁺]_i to increase by 268 ± 40 nM (n = 21) and 295 ± 53 nM (n = 21), respectively, whereas in response to 2MesATP and ADP, [Ca²⁺]_i increased by only 67 ± 13 nM (n = 8) and 93 ± 36 nM (n = 14), respectively. Dose response curve for ATP (10^-7 to 10^-3 M) added in bath showed an EC₅₀ of 15 µM. No effect on macula densa [Ca²⁺]_i was seen when ATP was added from the lumen. ATP caused similar increases in macula densa [Ca²⁺]_i in the presence or absence of bath Ca²⁺ and addition of 5 mM ethyleneglycotetraacetic acid (EGTA). Suramin (an antagonist of P2X and P2Y receptors) completely inhibited ATP-induced [Ca²⁺]_i dynamics. Also, ATP-Ca²⁺ responsiveness was prevented by the phospholipase C inhibitor, U-73122, but not by its inactive analog, U-73343. These results suggest that macula densa cells possess P2Y₂ purinergic receptors on basolateral but not apical membranes and that activation of these receptors results in the mobilization of Ca²⁺.

This article has been cited by other articles:

				R. Liu, O. A. Carretero, Y. Ren, H. Wang, and J. L. Garvin Intracellular pH regulates superoxide production by the macula densa Am J Physiol Renal Physiol, September 1, 2008; 295(3): F851 - F856. [Abstract] [Full Text] [PDF]

				V. Vallon P2 receptors in the regulation of renal transport mechanisms Am J Physiol Renal Physiol, January 1, 2008; 294(1): F10 - F27. [Abstract] [Full Text] [PDF]

				Z. Guan, D. A. Osmond, and E. W. Inscho Purinoceptors in the Kidney Experimental Biology and Medicine, June 1, 2007; 232(6): 715 - 726. [Abstract] [Full Text] [PDF]

				R. Liu and A. E. G Persson Simultaneous changes of cell volume and cytosolic calcium concentration in macula densa cells caused by alterations of luminal NaCl concentration J. Physiol., March 15, 2005; 563(3): 895 - 901. [Abstract] [Full Text] [PDF]

				P. A. Kemp, R. A. Sugar, and A. D. Jackson Nucleotide-Mediated Mucin Secretion from Differentiated Human Bronchial Epithelial Cells Am. J. Respir. Cell Mol. Biol., October 1, 2004; 31(4): 446 - 455. [Abstract] [Full Text] [PDF]

				R. Liu and A. E. G. Persson Angiotensin II Stimulates Calcium and Nitric Oxide Release From Macula Densa Cells Through AT1 Receptors Hypertension, March 1, 2004; 43(3): 649 - 653. [Abstract] [Full Text] [PDF]

				R. J. Unwin, M. A. Bailey, and G. Burnstock Purinergic Signaling Along the Renal Tubule: The Current State of Play Physiology, December 1, 2003; 18(6): 237 - 241. [Abstract] [Full Text] [PDF]

				R. Liu, J. Pittner, and A. E. G. Persson Changes of Cell Volume and Nitric Oxide Concentration in Macula Densa Cells Caused by Changes in Luminal NaCl Concentration J. Am. Soc. Nephrol., November 1, 2002; 13(11): 2688 - 2696. [Abstract] [Full Text] [PDF]

Copyright © 2008 by the American Society of Nephrology. Online ISSN: 1533-3450 Print ISSN: 1046-6673