Document Detail


Ex situ inhibition of hepatic uptake and efflux significantly changes metabolism: hepatic enzyme-transporter interplay.
MedLine Citation:
PMID:  14634033     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The disposition of digoxin and the influence of the organic anion transporting polypeptide (Oatp)2 inhibitor rifampicin and the P-glycoprotein (P-gp) inhibitor quinidine on its hepatic disposition were examined in the isolated perfused rat liver. Livers from groups of rats were perfused in a recirculatory manner after a bolus dose of digoxin (10 microg), a dual substrate for Oatp2 and P-gp as well as CYP3A. Perfusions of digoxin were also examined in groups of rats in the presence of the inhibitors: rifampicin (100 microM) or quinidine (10 microM). In all experiments, perfusate samples were collected for 60 min. Digoxin and its primary metabolite were determined in perfusate and liver by liquid chromatography/mass spectrometry. The area under the curve (AUC) from 0 to 60 min was determined. The AUC +/- S.D. of digoxin was increased from control (3880 +/- 210 nM x min) by rifampicin (5200 +/- 240 nM x min; p < 0.01) and decreased by quinidine (3220 +/- 340 nM x min; P < 0.05). It is concluded that rifampicin limits the hepatic entrance of digoxin and reduced the hepatic exposure of digoxin to CYP3A by inhibiting the basolateral Oatp2 uptake transport, whereas quinidine increased the hepatic exposure of digoxin to CYP3A by inhibiting the canalicular P-gp transport. These data emphasize the importance of uptake and efflux transporters on hepatic drug metabolism.
Authors:
Yvonne Y Lau; Chi-Yuan Wu; Hideaki Okochi; Leslie Z Benet
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2003-11-21
Journal Detail:
Title:  The Journal of pharmacology and experimental therapeutics     Volume:  308     ISSN:  0022-3565     ISO Abbreviation:  J. Pharmacol. Exp. Ther.     Publication Date:  2004 Mar 
Date Detail:
Created Date:  2004-02-26     Completed Date:  2004-04-06     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0376362     Medline TA:  J Pharmacol Exp Ther     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1040-5     Citation Subset:  IM    
Affiliation:
Department of Biopharmaceutical Sciences, University of California, San Francisco, San Francisco, CA 9414-0446, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Biological Transport
Digoxin / metabolism*
Liver / drug effects*,  metabolism
Male
Membrane Transport Proteins
Perfusion
Quinidine / pharmacokinetics
Rats
Rats, Sprague-Dawley
Rifampin / pharmacokinetics
Grant Support
ID/Acronym/Agency:
GM-61390/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Membrane Transport Proteins; 13292-46-1/Rifampin; 20830-75-5/Digoxin; 56-54-2/Quinidine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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