|
|
||||||||
cotransporter: a new model for ions
and diuretics interaction
1 Molecular Physiology Unit, Instituto Nacional de la Nutrición Salvador Zubirán and Instituto de Investigaciones Biomédicas, National University of Mexico, Tlalpan 14000 Mexico City, Mexico; and 2 Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232
The thiazide-sensitive
Na+-Cl
cotransporter (TSC) is the major
pathway for salt reabsorption in the apical membrane of the mammalian
distal convoluted tubule. When expressed in Xenopus laevis oocytes, rat TSC exhibits high affinity for both
cotransported ions, with the Michaelis-Menten constant
(Km) for Na+ of 7.6 ± 1.6 mM
and for Cl
of 6.3 ± 1.1 mM, and Hill coefficients
for Na+ and Cl
consistent with
electroneutrality. The affinities of both Na+ and
Cl
were increased by increasing concentration of the
counterion. The IC50 values for thiazides were affected by
both extracellular Na+ and Cl
. The higher the
Na+ or Cl
concentration, the lower the
inhibitory effect of thiazides. Finally, rTSC function is affected by
extracellular osmolarity. We propose a transport model featuring a
random order of binding in which the binding of each ion facilitates
the binding of the counterion. Both ion binding sites alter
thiazide-mediated inhibition of transport, indicating that the
thiazide-binding site is either shared or modified by both
Na+ and Cl
.
metolazone; distal tubule; osmolarity; salt reabsorption
This article has been cited by other articles:
![]() |
G. Gamba The thiazide-sensitive Na+-Cl- cotransporter: molecular biology, functional properties, and regulation by WNKs Am J Physiol Renal Physiol, October 1, 2009; 297(4): F838 - F848. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y.-F. Wang, Y.-C. Tseng, J.-J. Yan, J. Hiroi, and P.-P. Hwang Role of SLC12A10.2, a Na-Cl cotransporter-like protein, in a Cl uptake mechanism in zebrafish (Danio rerio) Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2009; 296(5): R1650 - R1660. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. San-Cristobal, D. Pacheco-Alvarez, C. Richardson, A. M. Ring, N. Vazquez, F. H. Rafiqi, D. Chari, K. T. Kahle, Q. Leng, N. A. Bobadilla, et al. Angiotensin II signaling increases activity of the renal Na-Cl cotransporter through a WNK4-SPAK-dependent pathway PNAS, March 17, 2009; 106(11): 4384 - 4389. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Moreno, P. S. Cristobal, M. Rivera, N. Vazquez, N. A. Bobadilla, and G. Gamba Affinity-defining Domains in the Na-Cl Cotransporter: A DIFFERENT LOCATION FOR Cl- AND THIAZIDE BINDING J. Biol. Chem., June 23, 2006; 281(25): 17266 - 17275. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Weinstein A mathematical model of rat distal convoluted tubule. I. Cotransporter function in early DCT Am J Physiol Renal Physiol, October 1, 2005; 289(4): F699 - F720. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Gamba Molecular Physiology and Pathophysiology of Electroneutral Cation-Chloride Cotransporters Physiol Rev, April 1, 2005; 85(2): 423 - 493. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. G. J. Hoenderop, B. Nilius, and R. J. M. Bindels Calcium Absorption Across Epithelia Physiol Rev, January 1, 2005; 85(1): 373 - 422. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. D Hughes How do thiazide and thiazide-like diuretics lower blood pressure? Journal of Renin-Angiotensin-Aldosterone System, December 1, 2004; 5(4): 155 - 160. [Abstract] [PDF] |
||||
![]() |
C. Tovar-Palacio, N. A. Bobadilla, P. Cortes, C. Plata, P. de los Heros, N. Vazquez, and G. Gamba Ion and diuretic specificity of chimeric proteins between apical Na+-K+-2Cl- and Na+-Cl- cotransporters Am J Physiol Renal Physiol, September 1, 2004; 287(3): F570 - F577. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Sabath, P. Meade, J. Berkman, P. d. l. Heros, E. Moreno, N. A. Bobadilla, N. Vazquez, D. H. Ellison, and G. Gamba Pathophysiology of functional mutations of the thiazide-sensitive Na-Cl cotransporter in Gitelman disease Am J Physiol Renal Physiol, August 1, 2004; 287(2): F195 - F203. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. A. Ferenczi, J. A. Fraser, S. Chawla, J. N. Skepper, C. J. Schwiening, and C. L.-H. Huang Membrane potential stabilization in amphibian skeletal muscle fibres in hypertonic solutions J. Physiol., March 1, 2004; 555(2): 423 - 438. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Hoover, E. Poch, A. Monroy, N. Vazquez, T. Nishio, G. Gamba, and S. C. Hebert N-Glycosylation at Two Sites Critically Alters Thiazide Binding and Activity of the Rat Thiazide-sensitive Na+:Cl- Cotransporter J. Am. Soc. Nephrol., February 1, 2003; 14(2): 271 - 282. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Frindt, T. McNair, A. Dahlmann, E. Jacobs-Palmer, and L. G. Palmer Epithelial Na channels and short-term renal response to salt deprivation Am J Physiol Renal Physiol, October 1, 2002; 283(4): F717 - F726. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Plata, P. Meade, N. Vazquez, S. C. Hebert, and G. Gamba Functional Properties of the Apical Na+-K+-2Cl- Cotransporter Isoforms J. Biol. Chem., March 22, 2002; 277(13): 11004 - 11012. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Mercado, P. de los Heros, N. Vazquez, P. Meade, D. B. Mount, and G. Gamba Functional and molecular characterization of the K-Cl cotransporter of Xenopus laevis oocytes Am J Physiol Cell Physiol, August 1, 2001; 281(2): C670 - C680. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Plata, P. Meade, A. Hall, R. C. Welch, N. Vazquez, S. C. Hebert, and G. Gamba Alternatively spliced isoform of apical Na+-K+-Cl{-} cotransporter gene encodes a furosemide-sensitive Na+-Cl{-}cotransporter Am J Physiol Renal Physiol, April 1, 2001; 280(4): F574 - F582. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Vazquez, A. Monroy, E. Dorantes, R. A. Munoz-Clares, and G. Gamba Functional differences between flounder and rat thiazide-sensitive Na-Cl cotransporter Am J Physiol Renal Physiol, April 1, 2002; 282(4): F599 - F607. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |