Non-steroidal anti-inflammatory drugs affect the methotrexate transport in IEC-6 cells.
Methotrexate (MTX) is used not only for the cancer chemotherapy but also for the treatment of rheumatic disease, often together with non-steroidal anti-inflammatory drugs (NSAIDs). MTX is actively cotransported with H(+) in the small intestine, mediated by a reduced folate carrier (RFC). The coadministration of some NSAIDs with MTX to rats caused a decrease of MTX absorption through the small intestine. This may be due to the uncoupling effect of oxidative phosphorylation of the NSAIDs. The present study investigated whether flufenamic acid, diclofenac and indomethacin, NSAIDs, decreased ATP content of rat-derived intestinal epithelial cell line IEC-6 cells and affected the MTX transport in IEC-6 cells. The MTX uptake in IEC-6 cells was dependent on medium pH and maximum around pH 4.5-5.5. The MTX uptake was composed of a transport inhibited by 4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid (DIDS) and a non-saturable one. The DIDS-sensitive component in the MTX uptake showed a saturation kinetics (Michaelis-Menten constant (Km): 3.91 +/- 0.52 microM, Maximum velocity (Vmax): 94.66 +/- 6.56 pmol/mg protein/5 min). The cellular ATP content in IEC-6 cells decreased significantly at 30 min after the cells were started to incubate with the NSAIDs (250 microM flufenamic acid, 500 microM diclofenac and 500 microM indomethacin). The MTX uptake in IEC-6 cells in the presence of the NSAIDs decreased with the reduction of cellular ATP content and showed a good correlation with the ATP content (correlation coefficient: 0.982). Thus it seems likely that the ATP content in IEC-6 cells with the NSAIDs decreased due to the uncoupling effect of oxidative phosphorylation of the NSAIDs, resulting in the inhibition of the secondary active transport of MTX in IEC-6 cells. The present results also suggest that IEC-6 cells are useful to evaluate the drug interaction relating to this carrier system.
Sosogi
Aiko
A
Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
Gao
Feng
F
Tomimatsu
Takashi
T
Hirata
Koji
K
Horie
Toshiharu
T
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001692:Biological Transport; D002460:Cell Line; D004396:Coloring Agents / Q000494:pharmacology; D004008:Diclofenac / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005439:Flufenamic Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007213:Indomethacin / Q000494:pharmacology; D007421:Intestine, Small / Q000187:drug effects; D007422:Intestines / Q000187:drug effects; D008727:Methotrexate / Q000494:pharmacology*; D010766:Phosphorylation; D051381:Rats; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004396:Coloring Agents; D004791:Enzyme Inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles; D004008:Diclofenac; D005439:Flufenamic Acid; D000255:Adenosine Triphosphate; C022616:thiazolyl blue; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D007213:Indomethacin; D008727:Methotrexate