Interaction of cysteine conjugates with human and rabbit organic anion transporter 1

Carlotta E. Groves, Lynn Muñoz, Andrew Bahn, Gerhard Burckhardt, Stephen Wright

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Organic anion (OA) transport mediates accumulation of the zwitterionic nephrotoxic cysteine S-conjugates S-dichlorovinylcysteine (DCVC) and S-chlorotrifluoroethylcysteine (CTFC) in the rabbit renal proximal tubule (RPT). Although these cysteine conjugates are nephrotoxic to the human RPT, neither the role of OA transport nor the specific OA transport pathway(s) involved in cysteine conjugate accumulation are known. Since the OAT1 transporter has the characteristics of para-aminokippurate (PAH) transport that closely correlate to the native RPT, we examined the interaction of DCVC, CTFC, and the nontoxic benzothiazolylcysteine (BTC) with PAH transport mediated by human OAT1 and rabbit Oat1 expressed in Chinese hamster ovary and COS7 heterologous expression systems, respectively. Although the Km values for PAH uptake by hOAT1 and rbOat1 (8.9 ± 3.6 and 20.7 ± 8 μM, respectively) were 5- to 10-fold less than the Km for peritubular PAH transport into rabbit RPT, the IC50 values for DCVC, CTFC, and BTC inhibition of PAH uptake mediated by either hOAT1 or rbOat1 were similar between these two transporters and to the IC50 values for these conjugates measured in rabbit RPT. The IC50 for inhibition of hOAT1- and rbOat1-mediated PAH uptake by the hydrophobic conjugate BTC was more than 5-fold lower than the IC50 values seen with DCVC and CTFC, suggesting that hydrophobicity increases the affinity of OAT1 for cysteine conjugates. Finally, preloading cells transfected with hOAT1 with BTC significantly trans-stimulated the uptake of PAH, consistent with the conclusion that BTC and, hence, other cysteine S-conjugates are substrates for hOAT1.

Original languageEnglish (US)
Pages (from-to)560-566
Number of pages7
JournalJournal of Pharmacology and Experimental Therapeutics
Volume304
Issue number2
DOIs
StatePublished - Feb 1 2003

Fingerprint

Organic Anion Transporters
Proximal Kidney Tubule
Cysteine
Inhibitory Concentration 50
Rabbits
Anions
Cricetulus
Hydrophobic and Hydrophilic Interactions
Ovary

ASJC Scopus subject areas

  • Pharmacology

Cite this

Interaction of cysteine conjugates with human and rabbit organic anion transporter 1. / Groves, Carlotta E.; Muñoz, Lynn; Bahn, Andrew; Burckhardt, Gerhard; Wright, Stephen.

In: Journal of Pharmacology and Experimental Therapeutics, Vol. 304, No. 2, 01.02.2003, p. 560-566.

Research output: Contribution to journalArticle

Groves, Carlotta E. ; Muñoz, Lynn ; Bahn, Andrew ; Burckhardt, Gerhard ; Wright, Stephen. / Interaction of cysteine conjugates with human and rabbit organic anion transporter 1. In: Journal of Pharmacology and Experimental Therapeutics. 2003 ; Vol. 304, No. 2. pp. 560-566.
@article{5a1899aad0064bd484c39d8d5957e2f9,
title = "Interaction of cysteine conjugates with human and rabbit organic anion transporter 1",
abstract = "Organic anion (OA) transport mediates accumulation of the zwitterionic nephrotoxic cysteine S-conjugates S-dichlorovinylcysteine (DCVC) and S-chlorotrifluoroethylcysteine (CTFC) in the rabbit renal proximal tubule (RPT). Although these cysteine conjugates are nephrotoxic to the human RPT, neither the role of OA transport nor the specific OA transport pathway(s) involved in cysteine conjugate accumulation are known. Since the OAT1 transporter has the characteristics of para-aminokippurate (PAH) transport that closely correlate to the native RPT, we examined the interaction of DCVC, CTFC, and the nontoxic benzothiazolylcysteine (BTC) with PAH transport mediated by human OAT1 and rabbit Oat1 expressed in Chinese hamster ovary and COS7 heterologous expression systems, respectively. Although the Km values for PAH uptake by hOAT1 and rbOat1 (8.9 ± 3.6 and 20.7 ± 8 μM, respectively) were 5- to 10-fold less than the Km for peritubular PAH transport into rabbit RPT, the IC50 values for DCVC, CTFC, and BTC inhibition of PAH uptake mediated by either hOAT1 or rbOat1 were similar between these two transporters and to the IC50 values for these conjugates measured in rabbit RPT. The IC50 for inhibition of hOAT1- and rbOat1-mediated PAH uptake by the hydrophobic conjugate BTC was more than 5-fold lower than the IC50 values seen with DCVC and CTFC, suggesting that hydrophobicity increases the affinity of OAT1 for cysteine conjugates. Finally, preloading cells transfected with hOAT1 with BTC significantly trans-stimulated the uptake of PAH, consistent with the conclusion that BTC and, hence, other cysteine S-conjugates are substrates for hOAT1.",
author = "Groves, {Carlotta E.} and Lynn Mu{\~n}oz and Andrew Bahn and Gerhard Burckhardt and Stephen Wright",
year = "2003",
month = "2",
day = "1",
doi = "10.1124/jpet.102.043455",
language = "English (US)",
volume = "304",
pages = "560--566",
journal = "Journal of Pharmacology and Experimental Therapeutics",
issn = "0022-3565",
publisher = "American Society for Pharmacology and Experimental Therapeutics",
number = "2",

}

TY - JOUR

T1 - Interaction of cysteine conjugates with human and rabbit organic anion transporter 1

AU - Groves, Carlotta E.

AU - Muñoz, Lynn

AU - Bahn, Andrew

AU - Burckhardt, Gerhard

AU - Wright, Stephen

PY - 2003/2/1

Y1 - 2003/2/1

N2 - Organic anion (OA) transport mediates accumulation of the zwitterionic nephrotoxic cysteine S-conjugates S-dichlorovinylcysteine (DCVC) and S-chlorotrifluoroethylcysteine (CTFC) in the rabbit renal proximal tubule (RPT). Although these cysteine conjugates are nephrotoxic to the human RPT, neither the role of OA transport nor the specific OA transport pathway(s) involved in cysteine conjugate accumulation are known. Since the OAT1 transporter has the characteristics of para-aminokippurate (PAH) transport that closely correlate to the native RPT, we examined the interaction of DCVC, CTFC, and the nontoxic benzothiazolylcysteine (BTC) with PAH transport mediated by human OAT1 and rabbit Oat1 expressed in Chinese hamster ovary and COS7 heterologous expression systems, respectively. Although the Km values for PAH uptake by hOAT1 and rbOat1 (8.9 ± 3.6 and 20.7 ± 8 μM, respectively) were 5- to 10-fold less than the Km for peritubular PAH transport into rabbit RPT, the IC50 values for DCVC, CTFC, and BTC inhibition of PAH uptake mediated by either hOAT1 or rbOat1 were similar between these two transporters and to the IC50 values for these conjugates measured in rabbit RPT. The IC50 for inhibition of hOAT1- and rbOat1-mediated PAH uptake by the hydrophobic conjugate BTC was more than 5-fold lower than the IC50 values seen with DCVC and CTFC, suggesting that hydrophobicity increases the affinity of OAT1 for cysteine conjugates. Finally, preloading cells transfected with hOAT1 with BTC significantly trans-stimulated the uptake of PAH, consistent with the conclusion that BTC and, hence, other cysteine S-conjugates are substrates for hOAT1.

AB - Organic anion (OA) transport mediates accumulation of the zwitterionic nephrotoxic cysteine S-conjugates S-dichlorovinylcysteine (DCVC) and S-chlorotrifluoroethylcysteine (CTFC) in the rabbit renal proximal tubule (RPT). Although these cysteine conjugates are nephrotoxic to the human RPT, neither the role of OA transport nor the specific OA transport pathway(s) involved in cysteine conjugate accumulation are known. Since the OAT1 transporter has the characteristics of para-aminokippurate (PAH) transport that closely correlate to the native RPT, we examined the interaction of DCVC, CTFC, and the nontoxic benzothiazolylcysteine (BTC) with PAH transport mediated by human OAT1 and rabbit Oat1 expressed in Chinese hamster ovary and COS7 heterologous expression systems, respectively. Although the Km values for PAH uptake by hOAT1 and rbOat1 (8.9 ± 3.6 and 20.7 ± 8 μM, respectively) were 5- to 10-fold less than the Km for peritubular PAH transport into rabbit RPT, the IC50 values for DCVC, CTFC, and BTC inhibition of PAH uptake mediated by either hOAT1 or rbOat1 were similar between these two transporters and to the IC50 values for these conjugates measured in rabbit RPT. The IC50 for inhibition of hOAT1- and rbOat1-mediated PAH uptake by the hydrophobic conjugate BTC was more than 5-fold lower than the IC50 values seen with DCVC and CTFC, suggesting that hydrophobicity increases the affinity of OAT1 for cysteine conjugates. Finally, preloading cells transfected with hOAT1 with BTC significantly trans-stimulated the uptake of PAH, consistent with the conclusion that BTC and, hence, other cysteine S-conjugates are substrates for hOAT1.

UR - http://www.scopus.com/inward/record.url?scp=0037309357&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037309357&partnerID=8YFLogxK

U2 - 10.1124/jpet.102.043455

DO - 10.1124/jpet.102.043455

M3 - Article

VL - 304

SP - 560

EP - 566

JO - Journal of Pharmacology and Experimental Therapeutics

JF - Journal of Pharmacology and Experimental Therapeutics

SN - 0022-3565

IS - 2

ER -