Thiamine is a substrate of organic cation transporters in Caco-2 cells

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Clara Lemos (Author) Other; Ana Faria (Author) FCUP; Manuela Meireles (Author) FMUP; Fatima Martel (Author) FMUP; Rosario Monteiro (Author) FMUP; Conceicao Calhau (Author) FMUP

Journal

Title: European Journal of Pharmacology

Vol. 682 No. 1-3

Pages: 37-42

ISSN: 0014-2999

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 25 Citations

ISI Web of Science

Scopus - 27 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

CORDIS: Health sciences > Pharmacological sciences > Clinical pharmacology

Other information

Authenticus ID: P-002-A4X

DOI: 10.1016/j.ejphar.2012.02.028

Abstract (EN): The aim of this study was to characterize the intestinal absorption of thiamine, by investigating the hypothesis of an involvement of Organic Cation Transporter (OCT) family members in this process. [H-3]-T+ uptake was found to be: 1) time-dependent, 2) Na+- and CI--dependent, 3) pH-dependent, with uptake increasing with a decrease in extracellular pH and decreasing with a decrease in intracellular pH, 4) inhibited by amiloride, 5) inhibited by the thiamine structural analogues oxythiamine and amprolium, 6) inhibited by the unrelated organic cations MPP, clonidine, dopamine, serotonin, 7) inhibited by the OCT inhibitors decynium22 and progesterone. Moreover, the dependence of [H-3]-T+ uptake on phosphorylation/dephosphorylation mechanisms was also investigated and [3H]-T+ uptake was found to be reduced by PKA activation and protein tyrosine phosphatase and alkaline phosphatase inhibition. In conclusion, our results are compatible with the possibility of thiamine being transported not only by ThTrl and/or ThTr2, but also by members of the OCT family of transporters (most probably OCT1 and/or OCT3), thus sharing the same transporters with several other organic cations at the small intestinal level.

Language: English

Type (Professor's evaluation): Scientific

Notes: <a href="http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Alerting&SrcApp=Alerting&DestApp=WOS&DestLinkType=FullRecord&KeyUT=000302982400005">Indexado na ISI Web of Science</a>

No. of pages: 6