ADMET & DMPK

Yazarlar: Malachy C. Ugwu, Ryan Pelis, Charles O. Esimone, Remigius U. Agu

Konular:-

DOI:10.5599/admet.5.2.389

Anahtar Kelimeler:Transporters,OCT2,CHO cells,Amiloride,Rhodamine,Fluorescence

Özet: The aim of this study was to assess the suitability of amiloride, rhodamine 6G and rhodamine 123 as non-radioactive substrates for characterizing hOCT2 using CHO cells. The uptake characteristics of these compounds were compared in wild-type (WT) and human organic cation transporter 2 (hOCT2)-stably transfected Chinese Hamster Ovary (CHO) cells. All the compounds were accumulated by the CHO-hOCT2 cells. Intracellular uptake of the compounds was higher in CHO cells stably-expressing hOCT2 compared to the WT. The uptake was concentration–dependent and saturable (except for rhodamine 123). The affinities of the compounds for the hOCT2 (in descending order) were: amiloride (Km = 72.63 12.02 μM) > rhodamine 6 G (Km = 82.47  29.15 μM). Uptake of amiloride in transfected cells was pH -dependent and significantly inhibited by hOCT2 inhibitors (quinine, verapamil and quinidine). Based on our kinetic data and other considerations, we recommend the use of amiloride for characterizing hOCT2 transporters.

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