TY - JOUR T1 - The Phenomenon of Albumin-Mediated Hepatic Uptake of Organic Anion Transport Polypeptide Substrates: Prediction of the In Vivo Uptake Clearance from the In Vitro Uptake by Isolated Hepatocytes Using a Facilitated-Dissociation Model JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 259 LP - 267 DO - 10.1124/dmd.117.077115 VL - 46 IS - 3 AU - Seiji Miyauchi AU - Masayuki Masuda AU - Soo-Jin Kim AU - Yuudai Tanaka AU - Kyeong-Ryoon Lee AU - Shouko Iwakado AU - Momoko Nemoto AU - Shotaro Sasaki AU - Kazumi Shimono AU - Yoshio Tanaka AU - Yuichi Sugiyama Y1 - 2018/03/01 UR - http://dmd.aspetjournals.org/content/46/3/259.abstract N2 - The effects of bovine serum albumin and human serum albumin on the unbound hepatic uptake clearance (PSu,inf) of the organic anion–transporting polypeptide substrates 1-anilino-8-naphthalene sulfonate (ANS) and pitavastatin (PTV) were determined using primary cultured rat hepatocytes and isolated human hepatocytes, respectively. The PSu,inf value of hepatocytes was estimated by dividing the initial uptake rate of these anions by their unbound concentrations. The PSu,inf values for ANS and PTV were enhanced in the presence of albumin, thereby demonstrating the phenomenon of “albumin-mediated” hepatic uptake. We previously constructed a “facilitated-dissociation” model, in which the interaction of the ligand-albumin complex with the cell surface enhanced the dissociation of that complex to provide unbound ligand for uptake to the hepatocytes [J Pharmacokinet Biopharm 16:165–181 (1988)]. That model was able to describe accurately the relationship between the enhancement of the PSu,inf values and the albumin concentration. By considering the enhancement of hepatic uptake clearance by albumin using this facilitated-dissociation model, we could predict accurately the PSu,inf in vivo from that obtained in isolated hepatocytes. In the light of these findings, we suggest that the facilitated-dissociation model is applicable to describing the phenomenon of albumin-mediated hepatic uptake via organic anion transporters and to evaluating hepatic uptake clearance in vivo. ER -