Published online before print January 12, 2004, doi: 10.1161/01.HYP.0000112421.18551.1e
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Hypertension. 2004;43:286.)
© 2004 American Heart Association, Inc.
Scientific Contributions |
Production and Role of Extracellular Guanosine Cyclic 3', 5' Monophosphate in Sodium Uptake in Human Proximal Tubule Cells
From the Departments of Medicine (S.S., H.M.S, R.M.C) and Pathology (J.J.G., R.A.F.), University of Virginia School of Medicine, Charlottesville.
Correspondence to Robert M. Carey, MD, MACP, Box 801414, University of Virginia Health System, Internal Medicine/Endocrinology, Charlottesville, VA 22908. E-mail rmc4c{at}virginia.edu
The present study was designed to determine the capability of human renal proximal tubule (RPT) to generate and export guanosine cyclic 3', 5' monophosphate (cGMP) in response to direct stimulation of soluble guanylyl cyclase by nitric oxide (NO) donors. In addition, we investigated whether cGMP extrusion from human RPT cells is required for inhibition of cellular sodium uptake. RPT cells were cultured from fresh human kidneys (normotensive subjects, n=4, mean age 65±4.7 years, 3 men, 1 woman; hypertensive patients, n=6, mean age 64±6.1 years, 4 men, 2 women) after unilateral nephrectomy. The fluorescence dye Sodium Green was employed to determine cytoplasmic Na+ concentration. In the presence of the Na+/K+ ATPase inhibitor ouabain, fluorescence was monitored at the appropriate wavelength (excitation 485 nm, emission 535 nm). Nitric oxide donor, S-nitroso-N-acetylpenicillamine (SNAP, 10-4 M), increased both intracellular and extracellular cGMP (from 1.26±0.21 to 88.7±12.6 pmol/mg protein and from 0.58±0.10 to 9.24±1.9 pmol/mL, respectively, P<0.01) and decreased cellular Na+ uptake by 37.4±6.8% (P<0.05) compared with control. The effects of SNAP on cGMP production were similar in normotensive and hypertensive subjects. The increases in intracellular and extracellular cGMP concentration because of SNAP were blocked completely by soluble guanylyl cyclase inhibitor ODQ (1-H-[1,2,4] oxadiazolo [4,2-alpha] quinoxalin-1-one). Probenecid, an organic anion transport inhibitor, augmented the SNAP (10-6 M)-induced increase in intracellular cGMP accumulation (from 4.9±0.9 to 9.8±1.5 pmol/mg protein, P<0.05), abrogated the SNAP-induced increase in extracellular cGMP extrusion (from 1.07±0.4 to 0.37±0.1 pmol/L, P<0.05) and blocked the SNAP-induced reduction in cellular Na+ uptake. Neither intracellular nor extracellular cGMP were influenced by L-arginine, the metabolic precursor of NO, or NG-nitro-L-arginine methyl ester, an inhibitor of NO synthase. After exogenous administration of cGMP (10-5 M) or its membrane-permeable analogue 8-Br-cGMP (10-5 M), only 8-Br-cGMP crossed the cell membrane to increase intracellular cGMP (from 1.36±0.19 to 289.7±29.4 pmol/mg protein, P<0.01). However, both cGMP and 8-Br-cGMP were effective in decreasing cellular Na+ uptake. In conclusion, human RPT cells contain soluble guanylyl cyclase and are able to generate and export cGMP in response to NO. Because human RPT cells do not themselves contain constitutive NO synthase, the NO-generating cGMP must be derived from sources outside the human RPT. The cGMP cellular export system is critical in the regulation of RPT cellular Na+ absorption in humans.
Key Words: extracellular cyclic GMP • nitric oxide • sodium
This article has been cited by other articles:
 |
|
 |
|
  D. C. Lieb, B. A. Kemp, N. L. Howell, J. J. Gildea, and R. M. Carey Reinforcing Feedback Loop of Renal Cyclic Guanosine 3' 5' -Monophosphate and Interstitial Hydrostatic Pressure in Pressure-Natriuresis Hypertension, December 1, 2009; 54(6): 1278 - 1283. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Park, B. A. Kemp, N. L. Howell, J. J. Gildea, S. R. Keller, and R. M. Carey Intact Microtubules Are Required for Natriuretic Responses to Nitric Oxide and Increased Renal Perfusion Pressure Hypertension, February 1, 2008; 51(2): 494 - 499. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Ahmed, B. A. Kemp, N. L. Howell, H. M. Siragy, and R. M. Carey Extracellular Renal Guanosine Cyclic 3'5'-Monophosphate Modulates Nitric Oxide and Pressure-Induced Natriuresis Hypertension, November 1, 2007; 50(5): 958 - 963. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Boerrigter, L. C. Costello-Boerrigter, A. Cataliotti, H. Lapp, J.-P. Stasch, and J. C. Burnett Jr Targeting Heme-Oxidized Soluble Guanylate Cyclase in Experimental Heart Failure Hypertension, May 1, 2007; 49(5): 1128 - 1133. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Esaki, K. Hoshijima, S. Kobayashi, H. Fukuda, K. Kawakami, and S. Hirose Visualization in zebrafish larvae of Na+ uptake in mitochondria-rich cells whose differentiation is dependent on foxi3a Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R470 - R480. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Herrera and J. L. Garvin Recent Advances in the Regulation of Nitric Oxide in the Kidney Hypertension, June 1, 2005; 45(6): 1062 - 1067. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-H. Jin, H. E. McGrath, J. J. Gildea, H. M. Siragy, R. A. Felder, and R. M. Carey Renal Interstitial Guanosine Cyclic 3', 5'-Monophosphate Mediates Pressure-Natriuresis Via Protein Kinase G Hypertension, May 1, 2004; 43(5): 1133 - 1139. [Abstract] [Full Text] [PDF]
|
|