title: Effect of OATP-binding on the prediction of biliary excretion.
abstract: 1. Biliary excretion of compounds is dependant on several transporter proteins for the active uptake of compounds from the blood into the hepatocytes. Organic anion-transporting polypeptides (OATPs) are some of the most abundant transporter proteins in the sinusoidal membrane and have been shown to have substrate specificity similar to the structural characteristics of cholephilic compounds. 2. In this study, we sought to use measures of OATP binding as predictors of biliary excretion in conjunction with molecular descriptors in a quantitative structure-activity relationship (QSAR) study. Percentage inhibitions of three subtypes of OATPs were used as surrogate indicators of OATP substrates. Several statistical modelling techniques were incorporated including classification and regression trees, boosted trees, random forest and multivariate adaptive regression splines (MARS) in order to first develop QSARs for the prediction of OATP inhibition of compounds. The predicted OATP percentage inhibition using selected models were then used as features of the QSAR models for the prediction of biliary excretion of compounds in rat. 3. The results indicated that incorporation of predicted OATP inhibition improves accuracy of biliary excretion models. The best result was obtained from a simple regression tree that used predicted OATP1B1 percentage inhibition at the root node of the tree.
authors.affiliation: a Medway School of Pharmacy, Universities of Kent and Greenwich , Chatham , Kent , UK.|b Division of Systems Biology , National Center for Toxicological Research, US Food and Drug Administration , Jefferson , AR , USA , and.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Sharifi
authors.affiliation: a Medway School of Pharmacy, Universities of Kent and Greenwich , Chatham , Kent , UK.|c School of Life Sciences, University of Sussex , Falmer , Brighton , UK.
authors.forename: Taravat
authors.initials: T
authors.lastname: Ghafourian
mesh_terms: D000818:Animals; D001692:Biological Transport; D065669:Hepatobiliary Elimination; D022781:Hepatocytes / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D015999:Multivariate Analysis; D027361:Organic Anion Transporters / Q000378:metabolism*; D021281:Quantitative Structure-Activity Relationship; D051381:Rats
chemical_list: D027361:Organic Anion Transporters
keywords: OATP; QSAR; anion transporters; excretion into bile; hepatic uptake