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Title: Uptake of 4-chloro-2-methylphenoxyacetic acid (MCPA) from the apical membrane of Caco-2 cells by the monocarboxylic acid transporter

Abstract

The cellular uptake mechanism of 4-chloro-2-methylphenoxyacetic acid (MCPA), a phenoxyacetic acid derivative, was investigated using Caco-2 epithelial cells. The cells were incubated with 50 {mu}M MCPA at pH 6.0 and 37 deg. C, and the uptake of MCPA from the apical membranes was measured. The uptake of MCPA was significantly decreased by incubation at low temperature (4 {sup o}C) and markedly increased by lowering the extracellular pH. Pretreatment with a protonophore, carbonylcyanide-p-(trifluoromethoxy)phenylhydrazone (25 {mu}M), or metabolic inhibitors, 2,4-dinitrophenol (1 mM) and sodium azide (10 mM), significantly decreased the uptake of MCPA by 53%, 45% and 48%, respectively. Coincubation of MCPA with 10 mM L-lactic acid or {alpha}-cyano-4-hydroxycinnamate, which is a substrate or an inhibitor of the monocarboxylic acid transporters (MCTs), significantly decreased the uptake of MCPA by 31% and 20%, respectively, and coincubation with benzoic acid profoundly decreased the uptake by 68%. In contrast, coincubation with succinic acid (a dicarboxylic acid) did not affect the uptake. Kinetic analysis of initial MCPA uptake suggested that MCPA is taken up via a carrier-mediated process [K{sub m} = 1.37 {+-} 0.15 mM, V{sub max} = 115 {+-} 6 nmol (mg protein){sup -1} (3 min){sup -1}]. Lineweaver-Burk plots show that benzoic acid competitively inhibitsmore » the uptake of MCPA with a K{sub i} value of 4.68 {+-} 1.76 mM. A trans-stimulation effect on MCPA uptake was found in cells preloaded with benzoic acid. These results suggest that the uptake of MCPA from the apical membrane of Caco-2 cells is mainly mediated by common MCTs along with benzoic acid but also in part by L-lactic acid.« less

Authors:
;  [1];  [1]
  1. Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Ishikari-Tobetsu, Hokkaido 061-0293 (Japan)
Publication Date:
OSTI Identifier:
21077947
Resource Type:
Journal Article
Journal Name:
Toxicology and Applied Pharmacology
Additional Journal Information:
Journal Volume: 227; Journal Issue: 3; Other Information: DOI: 10.1016/j.taap.2007.10.028; PII: S0041-008X(07)00502-9; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0041-008X
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; AZIDES; BENZOIC ACID; CELL MEMBRANES; DINITROPHENOL; LACTIC ACID; PH VALUE; PROTEINS; SODIUM; STIMULATION; SUCCINIC ACID; UPTAKE

Citation Formats

Kimura, Osamu, Tsukagoshi, Kensuke, and Endo, Tetsuya. Uptake of 4-chloro-2-methylphenoxyacetic acid (MCPA) from the apical membrane of Caco-2 cells by the monocarboxylic acid transporter. United States: N. p., 2008. Web. doi:10.1016/j.taap.2007.10.028.
Kimura, Osamu, Tsukagoshi, Kensuke, & Endo, Tetsuya. Uptake of 4-chloro-2-methylphenoxyacetic acid (MCPA) from the apical membrane of Caco-2 cells by the monocarboxylic acid transporter. United States. https://doi.org/10.1016/j.taap.2007.10.028
Kimura, Osamu, Tsukagoshi, Kensuke, and Endo, Tetsuya. 2008. "Uptake of 4-chloro-2-methylphenoxyacetic acid (MCPA) from the apical membrane of Caco-2 cells by the monocarboxylic acid transporter". United States. https://doi.org/10.1016/j.taap.2007.10.028.
@article{osti_21077947,
title = {Uptake of 4-chloro-2-methylphenoxyacetic acid (MCPA) from the apical membrane of Caco-2 cells by the monocarboxylic acid transporter},
author = {Kimura, Osamu and Tsukagoshi, Kensuke and Endo, Tetsuya},
abstractNote = {The cellular uptake mechanism of 4-chloro-2-methylphenoxyacetic acid (MCPA), a phenoxyacetic acid derivative, was investigated using Caco-2 epithelial cells. The cells were incubated with 50 {mu}M MCPA at pH 6.0 and 37 deg. C, and the uptake of MCPA from the apical membranes was measured. The uptake of MCPA was significantly decreased by incubation at low temperature (4 {sup o}C) and markedly increased by lowering the extracellular pH. Pretreatment with a protonophore, carbonylcyanide-p-(trifluoromethoxy)phenylhydrazone (25 {mu}M), or metabolic inhibitors, 2,4-dinitrophenol (1 mM) and sodium azide (10 mM), significantly decreased the uptake of MCPA by 53%, 45% and 48%, respectively. Coincubation of MCPA with 10 mM L-lactic acid or {alpha}-cyano-4-hydroxycinnamate, which is a substrate or an inhibitor of the monocarboxylic acid transporters (MCTs), significantly decreased the uptake of MCPA by 31% and 20%, respectively, and coincubation with benzoic acid profoundly decreased the uptake by 68%. In contrast, coincubation with succinic acid (a dicarboxylic acid) did not affect the uptake. Kinetic analysis of initial MCPA uptake suggested that MCPA is taken up via a carrier-mediated process [K{sub m} = 1.37 {+-} 0.15 mM, V{sub max} = 115 {+-} 6 nmol (mg protein){sup -1} (3 min){sup -1}]. Lineweaver-Burk plots show that benzoic acid competitively inhibits the uptake of MCPA with a K{sub i} value of 4.68 {+-} 1.76 mM. A trans-stimulation effect on MCPA uptake was found in cells preloaded with benzoic acid. These results suggest that the uptake of MCPA from the apical membrane of Caco-2 cells is mainly mediated by common MCTs along with benzoic acid but also in part by L-lactic acid.},
doi = {10.1016/j.taap.2007.10.028},
url = {https://www.osti.gov/biblio/21077947}, journal = {Toxicology and Applied Pharmacology},
issn = {0041-008X},
number = 3,
volume = 227,
place = {United States},
year = {Sat Mar 15 00:00:00 EDT 2008},
month = {Sat Mar 15 00:00:00 EDT 2008}
}