Related Experiment Video
Updated: Jun 21, 2026

An Intestine/Liver Microphysiological System for Drug Pharmacokinetic and Toxicological Assessment
Published on: December 3, 2020
Impact of regulatory polymorphisms in organic anion transporter genes in the human liver
Masayo Aoki1, Tomohiro Terada, Ken Ogasawara
1Department of Pharmacy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
Objectives:
The aim of this study was to evaluate whether genetic polymorphisms are responsible for individual variation in the expression levels of hepatic organic anion transporters.
Methods:
The mRNA levels of multidrug resistance-associated protein 2, organic anion transporting polypeptide (OATP) 1B1, OATP1B3 and OATP2B1 were determined by real-time polymerase chain reaction using liver tissue samples from 102 Japanese. The association between the mRNA levels of these transporters and the disappearance rate of indocyanine green was examined. The promoter region of each transporter gene was sequenced and the effects of single nucleotide polymorphisms (SNPs) in the promoter region [regulatory SNPs (rSNPs)] on mRNA levels were evaluated. Western blot analysis using hepatic crude plasma membrane was carried out to assess protein levels.
Results:
Expression levels of hepatic organic anion transporters vary considerably among individuals and possible links were observed between mRNA levels of these transporters and the disappearance rate of indocyanine green. In the OATP2B1 promoter region, we identified an rSNP (-282G > A) that significantly increased mRNA expression. Western blot analysis showed a remarkable increase in the OATP2B1 protein level in the homozygotes for the rSNP with a high mRNA level. In contrast, none of the rSNPs of multidrug resistance-associated protein 2, OATP1B1 and OATP1B3 affected the mRNA expression.
Conclusion:
OATP2B1 -282G > A is a major factor affecting expression, suggesting a contribution to inter-individual differences in the expression level of OATP2B1.
Related Concept Videos
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Nonlinear Pharmacokinetics: Role of Transporters
Polymorphisms occurring in drug transporters can alter...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Pharmacogenetics of Drug Metabolism: Overview
