TABLE 1

Contributions of OATP1B1 and OATP1B3 to Hepatic Uptake of (15R)-TIC in Humans^*

	Relative activity factor for:		CL_{hepatocyte, (15}_{R)-TIC (predicted)} (μL/min/10⁶ cells)			CL_{hepatocyte, (15}_{R)-TIC (observed)} (μL/min/10⁶ cells)
Hepatocyte lot	OATP1B1	OATP1B3	OATP1B1 mediated^†	OATP1B3 mediated^†	Sum	CL_{hepatocyte, (15}_{R)-TIC (observed)} (μL/min/10⁶ cells)
609	1.19	0.0728	14.4 (90.5)	1.51 (9.5)	16.0	43.4
NPX	0.466	0.138	5.64 (66.3)	2.87 (33.7)	8.51	10.0
03-006	0.195	0.0498	2.36 (69.5)	1.04 (30.5)	3.39	5.72
03-013	0.199	0.111	2.40 (51.0)	2.31 (49.0)	4.72	6.71
Average % for 4 lots (mean ± SD)			69.3 ± 16.3	30.7 ± 16.3

↵* Uptake of ³H-labeled estrone-3-sulfate (reference compound for OATP1B1) and ³H-labeled cholecystokinin octapeptide (reference compound for OATP1B3) was determined in OATP1B1- and OATP1B3-expressing cells, respectively. Uptake of (15R)-TIC (1 μM) for 1 min in these cells was also determined, and uptake clearance into OATP1B1-expressing cells (CL_{OATP1B1, (15R)-TIC}) and uptake clearance into OATP1B3-expressing cells (CL_{OATP1B3, (15R)-TIC}) were calculated as 12.1 and 20.8 μL/min/mg of protein, respectively.
↵† Values in parentheses are percentages of OATP1B1- and OATP1B3-mediated uptake clearance relative to sum of estimated clearances mediated by transporters. Details of this estimation (Eqs. 4–8) are given in Materials and Methods.