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 language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Renal Physiology |
| Volume | 286 |
| Issue number | 1 55-1 |
| State | Published - Jan 2004 |
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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 journal › Article
}
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 -