This Article Full Text Full Text (PDF) All Versions of this Article: 47/3/563    most recent 01.HYP.0000197954.93874.efv1 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Silva, G. Articles by Garvin, J. L. Search for Related Content PubMed PubMed Citation Articles by Silva, G. Articles by Garvin, J. L. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB FLUORESCEIN NITRIC OXIDE Related Collections Oxidant stress Receptor pharmacology

(Hypertension. 2006;47:563.)
© 2006 American Heart Association, Inc.

Part 2 Original Articles

Extracellular ATP Stimulates NO Production in Rat Thick Ascending Limb

From the Division of Hypertension and Vascular Research (G.S., W.H.B., J.L.G.), Henry Ford Hospital and Department of Physiology (W.H.B., J.L.G.), School of Medicine, Wayne State University, Detroit, Mich.

Correspondence to Jeffrey L. Garvin, Division of Hypertension and Vascular Research, Henry Ford Hospital, 2799 W Grand Blvd, Detroit, MI 48202. E-mail jgarvin1{at}hfhs.org

NO produced by NO synthase (NOS) 3 acts as an autacoid to regulate NaCl absorption in the thick ascending limb. ATP induces NO production by NOS 3 in endothelial cells. We hypothesized that extracellular ATP activates NOS in thick ascending limbs through P2 receptors. To test this, we measured intracellular NO production using the NO-selective fluorescent dye DAF-2 in suspensions of rat medullary thick ascending limbs. We found that ATP increased DAF-2 fluorescence in a concentration-dependent manner, reaching saturation at &200 µmol/L with an EC₅₀ of 37 µmol/L. The increase was blunted by 74% by the nonselective NOS inhibitor L--nitro-arginine-methyl-ester (2 mmol/L; 60±7 versus 16±6 arbitrary fluorescence units; P<0.02; n=5). In the presence of the P2 receptor antagonist suramin (300 µmol/L), ATP-induced NO production was reduced by 64% (101±11 versus 37±5 arbitrary fluorescence units; P<0.002; n=5). Blocking ATP hydrolysis with a 5'-ectonucleotidase inhibitor, ARL67156 (30 µmol/L) enhanced the response to ATP and shifted the EC₅₀ to 0.8 µmol/L. In the presence of ARL67156, the EC₅₀ of the P2X-selective agonist ß,-methylene-adenosine 5'-triphosphate was 4.8 µmol/L and the EC₅₀ for the P2Y–selective agonist UTP was 40.4 µmol/L. The maximal responses for both agonists were similar. Taken together, these data indicate that ATP stimulates NO production in the thick ascending limb primarily through P2X receptor activation and that ATP hydrolysis may regulate NO production.

Key Words: nitric oxide • kidney • receptors, purinergic • signal transduction

This article has been cited by other articles:

				G. B. Silva and J. L. Garvin Extracellular ATP inhibits transport in medullary thick ascending limbs: role of P2X receptors Am J Physiol Renal Physiol, November 1, 2009; 297(5): F1168 - F1173. [Abstract] [Full Text] [PDF]

				J. Yang, P. H. Lane, J. S. Pollock, and P. K Carmines PKC-dependent superoxide production by the renal medullary thick ascending limb from diabetic rats Am J Physiol Renal Physiol, November 1, 2009; 297(5): F1220 - F1228. [Abstract] [Full Text] [PDF]

				E. W. Inscho Purinoceptor regulation of renal tubular transport is coming of age Am J Physiol Renal Physiol, November 1, 2009; 297(5): F1166 - F1167. [Full Text] [PDF]

				G. B. Silva and J. L. Garvin Akt1 mediates purinergic-dependent NOS3 activation in thick ascending limbs Am J Physiol Renal Physiol, September 1, 2009; 297(3): F646 - F652. [Abstract] [Full Text] [PDF]

				S.-J. Wu and J.-Y. Wu Extracellular ATP-induced NO production and its dependence on membrane Ca2+ flux in Salvia miltiorrhiza hairy roots J. Exp. Bot., October 1, 2008; 59(14): 4007 - 4016. [Abstract] [Full Text] [PDF]

				G. B. Silva and J. L. Garvin TRPV4 mediates hypotonicity-induced ATP release by the thick ascending limb Am J Physiol Renal Physiol, October 1, 2008; 295(4): F1090 - F1095. [Abstract] [Full Text] [PDF]

				B. Mehta, G. Begum, N. B. Joshi, and P. G. Joshi Nitric Oxide-mediated Modulation of Synaptic Activity by Astrocytic P2Y Receptors J. Gen. Physiol., August 25, 2008; 132(3): 339 - 349. [Abstract] [Full Text] [PDF]

				S. A. Kempson, J. M. Edwards, A. Osborn, and M. Sturek Acute inhibition of the betaine transporter by ATP and adenosine in renal MDCK cells Am J Physiol Renal Physiol, July 1, 2008; 295(1): F108 - F117. [Abstract] [Full Text] [PDF]

				G. B. Silva, P. A. Ortiz, N. J. Hong, and J. L. Garvin Superoxide Stimulates NaCl Absorption in the Thick Ascending Limb Via Activation of Protein Kinase C Hypertension, September 1, 2006; 48(3): 467 - 472. [Abstract] [Full Text] [PDF]

				M. Herrera, P. A. Ortiz, and J. L. Garvin Regulation of thick ascending limb transport: role of nitric oxide Am J Physiol Renal Physiol, June 1, 2006; 290(6): F1279 - F1284. [Abstract] [Full Text] [PDF]