TY - JOUR
T1 - Identification and characterization of efflux transporters that modulate the subtoxic disposition of diclofenac and its metabolites
AU - Scialis, Renato J.
AU - Aleksunes, Lauren M.
AU - Csanaky, Iván L.
AU - Klaassen, Curtis D.
AU - Manautou, José E.
N1 - Publisher Copyright: © 2019 by The American Society for Pharmacology and Experimental Therapeutics.
PY - 2019
Y1 - 2019
N2 - In the present work, in vivo transporter knockout (KO) mouse models were used to characterize the disposition of diclofenac (DCF) and its primary metabolites following a single subtoxic dose in mice lacking breast cancer resistance protein (Bcrp) or multidrug resistance-associated protein (Mrp)3. The results indicate that Bcrp acts as a canalicular efflux mediator for DCF, as wild-type (WT) mice had biliary excretion values that were 2.2-to 2.6-fold greater than Bcrp KO mice, although DCF plasma levels were not affected. The loss of Bcrp resulted in a 1.8-to 3.2-fold increase of diclofenac acyl glucuronide (DCF-AG) plasma concentrations in KO animals compared with WT mice, while the biliary excretion of DCF-AG increased 1.4-fold in WT versus KO mice. Furthermore, Mrp3 was found to mediate the basolateral transport of DCF-AG, but not DCF or 4'-hydroxy diclofenac. WT mice had DCF-AG plasma concentrations 7.0-to 8.6-fold higher than Mrp3 KO animals; however, there were no changes in biliary excretion of DCF-AG. Vesicular transport experiments with human MRP3 demonstrated that MRP3 is able to transport DCF-AG via low-and high-affinity binding sites. The lowaffinity MRP3 transport had a Vmax and Km of 170 pmol/min/mg and 98.2 mM, respectively, while the high-affinity Vmax and Km parameters were estimated to be 71.9 pmol/min/mg and 1.78 mM, respectively. In summary, we offer evidence that the disposition of DCF-AG can be affected by both Bcrp andMrp3, and these findings may be applicable to humans.
AB - In the present work, in vivo transporter knockout (KO) mouse models were used to characterize the disposition of diclofenac (DCF) and its primary metabolites following a single subtoxic dose in mice lacking breast cancer resistance protein (Bcrp) or multidrug resistance-associated protein (Mrp)3. The results indicate that Bcrp acts as a canalicular efflux mediator for DCF, as wild-type (WT) mice had biliary excretion values that were 2.2-to 2.6-fold greater than Bcrp KO mice, although DCF plasma levels were not affected. The loss of Bcrp resulted in a 1.8-to 3.2-fold increase of diclofenac acyl glucuronide (DCF-AG) plasma concentrations in KO animals compared with WT mice, while the biliary excretion of DCF-AG increased 1.4-fold in WT versus KO mice. Furthermore, Mrp3 was found to mediate the basolateral transport of DCF-AG, but not DCF or 4'-hydroxy diclofenac. WT mice had DCF-AG plasma concentrations 7.0-to 8.6-fold higher than Mrp3 KO animals; however, there were no changes in biliary excretion of DCF-AG. Vesicular transport experiments with human MRP3 demonstrated that MRP3 is able to transport DCF-AG via low-and high-affinity binding sites. The lowaffinity MRP3 transport had a Vmax and Km of 170 pmol/min/mg and 98.2 mM, respectively, while the high-affinity Vmax and Km parameters were estimated to be 71.9 pmol/min/mg and 1.78 mM, respectively. In summary, we offer evidence that the disposition of DCF-AG can be affected by both Bcrp andMrp3, and these findings may be applicable to humans.
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U2 - 10.1124/dmd.119.086603
DO - 10.1124/dmd.119.086603
M3 - Article
C2 - 31399506
SN - 0090-9556
VL - 47
SP - 1080
EP - 1092
JO - Drug Metabolism and Disposition
JF - Drug Metabolism and Disposition
IS - 10
ER -