TY - JOUR
T1 - Active Pharmaceutical Ingredient Uptake by Zebrafish (Danio rerio) Oct2 (slc22a2) Transporter Expressed in Xenopus laevis Oocytes
AU - Hogstrand, Christer
N1 - Funding Information:
The present study was conducted under funding awarded to NRB from the Biotechnology and Biological Sciences Research Council (BBSRC) CASE industrial scholarship scheme (Reference No. BB/M014827/1) and the AstraZeneca Global Sustainability Research Programme.
Publisher Copyright:
© 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
PY - 2022/12
Y1 - 2022/12
N2 - Uptake of active pharmaceutical ingredients (APIs) across the gill epithelium of fish is via either a passive or facilitated transport process, with the latter being more important at the lower concentrations more readily observed in the environment. The solute carrier (SLC) 22A family, which includes the organic cation transporter OCT2 (SLC22A2), has been shown in mammals to transport several endogenous chemicals and APIs. Zebrafish oct2 was expressed in Xenopus oocytes and the uptake of ranitidine, propranolol, and tetraethylammonium characterized. Uptake of ranitidine and propranolol was time- and concentration-dependent with a k
m and V
max for ranitidine of 246 µM and 45 pmol/(oocyte × min) and for propranolol of 409 µM and 190 pmol/(oocyte × min), respectively. Uptake of tetraethylammonium (TEA) was inhibited by propranolol, amantadine, and cimetidine, known to be human OCT2 substrates, but not quinidine or ranitidine. At external media pH 7 and 8 propranolol uptake was 100-fold greater than at pH 6; pH did not affect ranitidine or TEA uptake. It is likely that cation uptake is driven by the electrochemical gradient across the oocyte. Uptake kinetics parameters, such as those derived in the present study, coupled with knowledge of transporter localization and abundance and API metabolism, can help derive pharmacokinetic models. Environ Toxicol Chem 2022;41:2993–2998.
AB - Uptake of active pharmaceutical ingredients (APIs) across the gill epithelium of fish is via either a passive or facilitated transport process, with the latter being more important at the lower concentrations more readily observed in the environment. The solute carrier (SLC) 22A family, which includes the organic cation transporter OCT2 (SLC22A2), has been shown in mammals to transport several endogenous chemicals and APIs. Zebrafish oct2 was expressed in Xenopus oocytes and the uptake of ranitidine, propranolol, and tetraethylammonium characterized. Uptake of ranitidine and propranolol was time- and concentration-dependent with a k
m and V
max for ranitidine of 246 µM and 45 pmol/(oocyte × min) and for propranolol of 409 µM and 190 pmol/(oocyte × min), respectively. Uptake of tetraethylammonium (TEA) was inhibited by propranolol, amantadine, and cimetidine, known to be human OCT2 substrates, but not quinidine or ranitidine. At external media pH 7 and 8 propranolol uptake was 100-fold greater than at pH 6; pH did not affect ranitidine or TEA uptake. It is likely that cation uptake is driven by the electrochemical gradient across the oocyte. Uptake kinetics parameters, such as those derived in the present study, coupled with knowledge of transporter localization and abundance and API metabolism, can help derive pharmacokinetic models. Environ Toxicol Chem 2022;41:2993–2998.
UR - http://www.scopus.com/inward/record.url?scp=85140095688&partnerID=8YFLogxK
U2 - 10.1002/etc.5480
DO - 10.1002/etc.5480
M3 - Article
SN - 0730-7268
VL - 41
SP - 2993
EP - 2998
JO - ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
JF - ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
IS - 12
ER -