Interaction of the metal chelator DMPS with OAT1 and OAT3 in intact isolated rabbit renal proximal tubules

A. Lungkaphin, V. Chatsudthipong, K. K. Evans, C. E. Groves, Stephen Wright, William H Dantzler

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

2,3-Dimercapto-1-propanesulfonic acid (DMPS) is used clinically to increase urinary excretion of heavy metals, including mercury and arsenic. We used single S2 segments and suspensions of rabbit renal proximal tubules (RPT) to test the interaction of this anionic heavy metal chelator with basolateral transporters OAT1 and OAT3. RT-PCR revealed expression of both transporters in single S2 segments. [3H]PAH and 3H-labeled estrone sulfate ([3H]ES) were used as specific substrates for rbOAT1 and rbOAT3, respectively. PAH and ES were transported into nonperfused single RPT segments with Kt values of 67 ± 20 and 3.4 ± 1.2 μM, respectively, and into tubule suspensions with Kt values of 58 ± 17 and 7.7 ± 2.1 μM, respectively. Reduced DMPS (DMPSH) inhibited uptake of both substrates into single tubule segments with K app values of 405 ± 49 μM (for [3H]PAH) and 320 ± 66 μM (for [3H]ES). Oxidized DMPS (DMPSS), the prevalent form in the blood, also inhibited uptakes of [3H]PAH (K app of 766 ± 190 μM) and [3H]ES (696 ± 166 μM). Inward gradients of ES, DMPSH, and DMPSS trans-stimulated the 30-s efflux of preloaded [3H]ES across the basolateral membrane of RPT. Similarly, DMPSH, and PAH itself, trans-stimulated the 15-s efflux of [ 3H]PAH. In contrast, efflux of [3H]PAH was inhibited by the presence of DMPSS in the bathing medium. These data suggest that, whereas both OAT1 and OAT3 probably transport DMPSH, DMPSS transport may be limited to OAT3. This is the first evidence showing that both OAT1 and OAT3 can transport DMPS across the basolateral membrane of RPT.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Physiology
Volume286
Issue number1 55-1
StatePublished - Jan 2004

Fingerprint

Unithiol
Proximal Kidney Tubule
Chelating Agents
Metals
Rabbits
Heavy Metals
Suspensions
Membranes
Arsenic
Mercury
Polymerase Chain Reaction

Keywords

  • Estrone sulfate
  • Kidney
  • Organic anion
  • p-aminohippurate
  • Transport

ASJC Scopus subject areas

  • Physiology

Cite this

Interaction of the metal chelator DMPS with OAT1 and OAT3 in intact isolated rabbit renal proximal tubules. / Lungkaphin, A.; Chatsudthipong, V.; Evans, K. K.; Groves, C. E.; Wright, Stephen; Dantzler, William H.

In: American Journal of Physiology - Renal Physiology, Vol. 286, No. 1 55-1, 01.2004.

Research output: Contribution to journalArticle

@article{1d5f3e0149c84e04ad915d32ecd6379a,
title = "Interaction of the metal chelator DMPS with OAT1 and OAT3 in intact isolated rabbit renal proximal tubules",
abstract = "2,3-Dimercapto-1-propanesulfonic acid (DMPS) is used clinically to increase urinary excretion of heavy metals, including mercury and arsenic. We used single S2 segments and suspensions of rabbit renal proximal tubules (RPT) to test the interaction of this anionic heavy metal chelator with basolateral transporters OAT1 and OAT3. RT-PCR revealed expression of both transporters in single S2 segments. [3H]PAH and 3H-labeled estrone sulfate ([3H]ES) were used as specific substrates for rbOAT1 and rbOAT3, respectively. PAH and ES were transported into nonperfused single RPT segments with Kt values of 67 ± 20 and 3.4 ± 1.2 μM, respectively, and into tubule suspensions with Kt values of 58 ± 17 and 7.7 ± 2.1 μM, respectively. Reduced DMPS (DMPSH) inhibited uptake of both substrates into single tubule segments with K app values of 405 ± 49 μM (for [3H]PAH) and 320 ± 66 μM (for [3H]ES). Oxidized DMPS (DMPSS), the prevalent form in the blood, also inhibited uptakes of [3H]PAH (K app of 766 ± 190 μM) and [3H]ES (696 ± 166 μM). Inward gradients of ES, DMPSH, and DMPSS trans-stimulated the 30-s efflux of preloaded [3H]ES across the basolateral membrane of RPT. Similarly, DMPSH, and PAH itself, trans-stimulated the 15-s efflux of [ 3H]PAH. In contrast, efflux of [3H]PAH was inhibited by the presence of DMPSS in the bathing medium. These data suggest that, whereas both OAT1 and OAT3 probably transport DMPSH, DMPSS transport may be limited to OAT3. This is the first evidence showing that both OAT1 and OAT3 can transport DMPS across the basolateral membrane of RPT.",
keywords = "Estrone sulfate, Kidney, Organic anion, p-aminohippurate, Transport",
author = "A. Lungkaphin and V. Chatsudthipong and Evans, {K. K.} and Groves, {C. E.} and Stephen Wright and Dantzler, {William H}",
year = "2004",
month = "1",
language = "English (US)",
volume = "286",
journal = "American Journal of Physiology",
issn = "0363-6143",
publisher = "American Physiological Society",
number = "1 55-1",

}

TY - JOUR

T1 - Interaction of the metal chelator DMPS with OAT1 and OAT3 in intact isolated rabbit renal proximal tubules

AU - Lungkaphin, A.

AU - Chatsudthipong, V.

AU - Evans, K. K.

AU - Groves, C. E.

AU - Wright, Stephen

AU - Dantzler, William H

PY - 2004/1

Y1 - 2004/1

N2 - 2,3-Dimercapto-1-propanesulfonic acid (DMPS) is used clinically to increase urinary excretion of heavy metals, including mercury and arsenic. We used single S2 segments and suspensions of rabbit renal proximal tubules (RPT) to test the interaction of this anionic heavy metal chelator with basolateral transporters OAT1 and OAT3. RT-PCR revealed expression of both transporters in single S2 segments. [3H]PAH and 3H-labeled estrone sulfate ([3H]ES) were used as specific substrates for rbOAT1 and rbOAT3, respectively. PAH and ES were transported into nonperfused single RPT segments with Kt values of 67 ± 20 and 3.4 ± 1.2 μM, respectively, and into tubule suspensions with Kt values of 58 ± 17 and 7.7 ± 2.1 μM, respectively. Reduced DMPS (DMPSH) inhibited uptake of both substrates into single tubule segments with K app values of 405 ± 49 μM (for [3H]PAH) and 320 ± 66 μM (for [3H]ES). Oxidized DMPS (DMPSS), the prevalent form in the blood, also inhibited uptakes of [3H]PAH (K app of 766 ± 190 μM) and [3H]ES (696 ± 166 μM). Inward gradients of ES, DMPSH, and DMPSS trans-stimulated the 30-s efflux of preloaded [3H]ES across the basolateral membrane of RPT. Similarly, DMPSH, and PAH itself, trans-stimulated the 15-s efflux of [ 3H]PAH. In contrast, efflux of [3H]PAH was inhibited by the presence of DMPSS in the bathing medium. These data suggest that, whereas both OAT1 and OAT3 probably transport DMPSH, DMPSS transport may be limited to OAT3. This is the first evidence showing that both OAT1 and OAT3 can transport DMPS across the basolateral membrane of RPT.

AB - 2,3-Dimercapto-1-propanesulfonic acid (DMPS) is used clinically to increase urinary excretion of heavy metals, including mercury and arsenic. We used single S2 segments and suspensions of rabbit renal proximal tubules (RPT) to test the interaction of this anionic heavy metal chelator with basolateral transporters OAT1 and OAT3. RT-PCR revealed expression of both transporters in single S2 segments. [3H]PAH and 3H-labeled estrone sulfate ([3H]ES) were used as specific substrates for rbOAT1 and rbOAT3, respectively. PAH and ES were transported into nonperfused single RPT segments with Kt values of 67 ± 20 and 3.4 ± 1.2 μM, respectively, and into tubule suspensions with Kt values of 58 ± 17 and 7.7 ± 2.1 μM, respectively. Reduced DMPS (DMPSH) inhibited uptake of both substrates into single tubule segments with K app values of 405 ± 49 μM (for [3H]PAH) and 320 ± 66 μM (for [3H]ES). Oxidized DMPS (DMPSS), the prevalent form in the blood, also inhibited uptakes of [3H]PAH (K app of 766 ± 190 μM) and [3H]ES (696 ± 166 μM). Inward gradients of ES, DMPSH, and DMPSS trans-stimulated the 30-s efflux of preloaded [3H]ES across the basolateral membrane of RPT. Similarly, DMPSH, and PAH itself, trans-stimulated the 15-s efflux of [ 3H]PAH. In contrast, efflux of [3H]PAH was inhibited by the presence of DMPSS in the bathing medium. These data suggest that, whereas both OAT1 and OAT3 probably transport DMPSH, DMPSS transport may be limited to OAT3. This is the first evidence showing that both OAT1 and OAT3 can transport DMPS across the basolateral membrane of RPT.

KW - Estrone sulfate

KW - Kidney

KW - Organic anion

KW - p-aminohippurate

KW - Transport

UR - http://www.scopus.com/inward/record.url?scp=0346729900&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0346729900&partnerID=8YFLogxK

M3 - Article

C2 - 13129851

AN - SCOPUS:0346729900

VL - 286

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6143

IS - 1 55-1

ER -