![]() |
|
|
JB Pritchard
Laboratory of Cellular and Molecular Pharmacology, National Institutes of Health, National Institute of Environmental Health Science, Research Triangle Park, North Carolina 27709, USA.
Renal organic anion secretion is driven by indirect coupling to the Na+ gradient at the basolateral membrane through Na(+)-dicarboxylate cotransport and dicarboxylate-organic anion exchange. The impact of changing intracellular alpha-ketoglutarate (alpha KG) concentrations and gradient on p-aminohippurate (PAH) transport was assessed in rat renal cortical slices. Fluorimetric analysis of alpha KG indicated that freshly isolated slices averaged 137 +/- 4 nmol/g wet weight (approximately 265 microM in cellular water). This value was sustained over several hours at 4 degrees C. On incubation at 22 degrees C, intracellular alpha KG concentrations rose steadily, reaching levels of 2 (air) to 4 (100% O2) times that of fresh tissue. When internal alpha KG was increased by preincubation and PAH uptake was determined at a fixed gradient, PAH transport increased with increasing internal alpha KG. Conversely, at a fixed internal alpha KG concentration, PAH uptake was a linear function of the driving force provided by the alpha KG gradient. Thus, intracellular alpha KG is a major determinant of the efficacy of renal organic anion transport, and events that alter internal alpha KG concentration, gradient, or both are poised to exert significant control over organic anion secretion. Kinetic analysis of alpha KG-PAH exchange indicated that the Km for alpha KG was 151 microM in basolateral membrane vesicles and 131 microM in slices. Because PAH transport increased at intracellular alpha KG concentrations that should have been saturating, this finding indicates that cytoplasmic alpha KG levels must be substantially lower than total tissue concentration, i.e., that much intracellular alpha KG must be sequestered.
This article has been cited by other articles:
![]() |
N. Anzai, P. Jutabha, A. Enomoto, H. Yokoyama, H. Nonoguchi, T. Hirata, K. Shiraya, X. He, S. H. Cha, M. Takeda, et al. Functional Characterization of Rat Organic Anion Transporter 5 (Slc22a19) at the Apical Membrane of Renal Proximal Tubules J. Pharmacol. Exp. Ther., November 1, 2005; 315(2): 534 - 544. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Soodvilai, S. H. Wright, W. H. Dantzler, and V. Chatsudthipong Involvement of tyrosine kinase and PI3K in the regulation of OAT3-mediated estrone sulfate transport in isolated rabbit renal proximal tubules Am J Physiol Renal Physiol, November 1, 2005; 289(5): F1057 - F1064. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Soodvilai, V. Chatsudthipong, K. K. Evans, S. H. Wright, and W. H. Dantzler Acute regulation of OAT3-mediated estrone sulfate transport in isolated rabbit renal proximal tubules Am J Physiol Renal Physiol, November 1, 2004; 287(5): F1021 - F1029. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. K. Zalups and S. Ahmad Homocysteine and the Renal Epithelial Transport and Toxicity of Inorganic Mercury: Role of Basolateral Transporter Organic Anion Transporter 1 J. Am. Soc. Nephrol., August 1, 2004; 15(8): 2023 - 2031. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. L. Youngblood and D. H. Sweet Identification and functional assessment of the novel murine organic anion transporter Oat5 (Slc22a19) expressed in kidney Am J Physiol Renal Physiol, August 1, 2004; 287(2): F236 - F244. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H. Wright and W. H. Dantzler Molecular and Cellular Physiology of Renal Organic Cation and Anion Transport Physiol Rev, July 1, 2004; 84(3): 987 - 1049. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Aslamkhan, Y.-H. Han, R. Walden, D. H. Sweet, and J. B. Pritchard Stoichiometry of organic anion/dicarboxylate exchange in membrane vesicles from rat renal cortex and hOAT1-expressing cells Am J Physiol Renal Physiol, October 1, 2003; 285(4): F775 - F783. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Sweet, L. M. S. Chan, R. Walden, X.-P. Yang, D. S. Miller, and J. B. Pritchard Organic anion transporter 3 (Slc22a8) is a dicarboxylate exchanger indirectly coupled to the Na+ gradient Am J Physiol Renal Physiol, April 1, 2003; 284(4): F763 - F769. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. Aslamkhan, Y.-H. Han, X.-P. Yang, R. K. Zalups, and J. B. Pritchard Human Renal Organic Anion Transporter 1-Dependent Uptake and Toxicity of Mercuric-Thiol Conjugates in Madin-Darby Canine Kidney Cells Mol. Pharmacol., March 1, 2003; 63(3): 590 - 596. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Tsutsumi, T. Deguchi, M. Takano, A. Takadate, W. E. Lindup, and M. Otagiri Renal Disposition of a Furan Dicarboxylic Acid and Other Uremic Toxins in the Rat J. Pharmacol. Exp. Ther., November 1, 2002; 303(2): 880 - 887. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. M. H. Van Aubel, R. Masereeuw, and F. G. M. Russel Molecular pharmacology of renal organic anion transporters Am J Physiol Renal Physiol, August 1, 2000; 279(2): F216 - F232. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Terlouw, O. Tanriseven, F. G. M. Russel, and R. Masereeuw Metabolite Anion Carriers Mediate the Uptake of the Anionic Drug Fluorescein in Renal Cortical Mitochondria J. Pharmacol. Exp. Ther., March 1, 2000; 292(3): 968 - 973. [Abstract] [Full Text] |
||||
![]() |
A. Shuprisha, R. M. Lynch, S. H. Wright, and W. H. Dantzler Real-time assessment of alpha -ketoglutarate effect on organic anion secretion in perfused rabbit proximal tubules Am J Physiol Renal Physiol, October 1, 1999; 277(4): F513 - F523. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Chatsudthipong, P. Jutabha, K. K. Evans, and W. H. Dantzler Effects of Inhibitors and Substitutes for Chloride in Lumen on p-Aminohippurate Transport by Isolated Perfused Rabbit Renal Proximal Tubules J. Pharmacol. Exp. Ther., March 1, 1999; 288(3): 993 - 1001. [Abstract] [Full Text] |
||||
![]() |
J. Nagai, I. Yano, Y. Hashimoto, M. Takano, and K.-I. Inui Efflux of Intracellular alpha -Ketoglutarate Via p-Aminohippurate/Dicarboxylate Exchange in OK Kidney Epithelial Cells J. Pharmacol. Exp. Ther., May 1, 1998; 285(2): 422 - 427. [Abstract] [Full Text] |
||||
![]() |
J. R. Welborn, S. Shpun, W. H. Dantzler, and S. H. Wright Effect of alpha -ketoglutarate on organic anion transport in single rabbit renal proximal tubules Am J Physiol Renal Physiol, January 1, 1998; 274(1): F165 - F174. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Sweet, N. A. Wolff, and J. B. Pritchard Expression Cloning and Characterization of ROAT1. THE BASOLATERAL ORGANIC ANION TRANSPORTER IN RAT KIDNEY J. Biol. Chem., November 28, 1997; 272(48): 30088 - 30095. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Nagai, I. Yano, Y. Hashimoto, M. Takano, and K.-I. Inui Inhibition of PAH transport by parathyroid hormone in OK cells: involvement of protein kinase C pathway Am J Physiol Renal Physiol, November 1, 1997; 273(5): F674 - F679. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. M. Edwards, E. Stack, and W. Trizna J. Pharmacol. Exp. Ther., June 1, 1997; 281(3): 1059 - 1064. [Abstract] [Full Text] |
||||