|
|
||||||||
Tulane Medical Center and Veterans Affairs Medical Center, New Orleans, Louisiana 70112
Urinary citrate, which
inhibits calcium nephrolithiasis, is determined by proximal
reabsorption via an apical dicarboxylate transporter. Citrate is
predominantly trivalent at physiological pH, but
citrate
2 is transported at the apical
membrane. We now demonstrate that low-Ca solutions induce transport of
citrate
2 and succinate in opossum kidney
cells. With 1.2 mM extracellular Ca, citrate uptake was pH insensitive
and not competed by succinate
2. In
contrast, with low extracellular Ca, citrate uptake increased twofold,
was inhibited by succinate (and other dicarboxylates), was stimulated
by lowering extracellular pH (consistent with
citrate
2 transport), and increased
further by lowering extracellular Mg. The effect of Ca was
incrementally concentration dependent, between 0 and 1.2 mM. The effect
of Ca was not simply complexation with citrate because succinate (which
is complexed significantly less) was affected by Ca similarly.
Incubation of cells for 48 h in a low-pH media increased citrate
transport (studied at control pH) more than twofold, suggesting
induction of transporters.
dicarboxylate; calcium; magnesium; acid-base; nephrolithiasis
This article has been cited by other articles:
![]() |
T. R. Van Vleet, M. R. White, T. P. Sanderson, S. M. Cohen, M. Cano, L. L. Arnold, C. R. Waites, B. E. Schilling, J. Mitroka, and M. A. Dominick Subchronic Urinary Bladder Effects of Muraglitazar in Male Rats Toxicol. Sci., March 1, 2007; 96(1): 58 - 71. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Mycielska and M. B. A. Djamgoz Citrate transport in the human prostate epithelial PNT2-C2 cell line: electrophysiological analyses J. Physiol., September 15, 2004; 559(3): 821 - 833. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Aruga, A. M. Pajor, K. Nakamura, L. Liu, O. W. Moe, P. A. Preisig, and R. J. Alpern OKP cells express the Na-dicarboxylate cotransporter NaDC-1 Am J Physiol Cell Physiol, July 1, 2004; 287(1): C64 - C72. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |