ADMET and DMPK, Vol. 5 No. 2, 2017.
Original scientific paper
https://doi.org/10.5599/admet.5.2.389
Fluorescent organic cations for human OCT2 transporters screening: uptake in CHO cells stably expressing hOCT2
Malachy C. Ugwu
; Biopharmaceutics and Drug Delivery Lab College of Pharmacy 5968 College Street, PO Box 15000, Halifax, NS B3H 4R2, CANADA
Ryan Pelis
; Department of Pharmacology Faculty of Medicine Dalhousie University P.O. Box 15000 Halifax, NS B3H 4R2
Charles O. Esimone
; Department of Pharmaceutical Microbiology & Biotechnology Faculty of Pharmaceutical Sciences Nnamdi Azikiwe University, Near NAFDAC Zonal Lab, Agulu, Anambra State, Nigeria
Remigius U. Agu
; Biopharmaceutics and Drug Delivery Lab College of Pharmacy 5968 College Street, PO Box 15000, Halifax, NS B3H 4R2, CANADA
Abstract
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.
Keywords
Transporters; OCT2; CHO cells; amiloride; rhodamine; fluorescence
Hrčak ID:
183286
URI
Publication date:
22.6.2017.
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