Table 1:

Saturation Kinetics of ³⁵S-BSP Uptake by HeLa Cells with Zn-dependent Expression of rOATP1A1 or both rOATP1A1 and rOATP1A4.

Cell Line	rOATP1A1			rOATP1A1 + rOATP1A4
Time after Zinc	0 hr	4 hr	24 hr	0 hr	4 hr	24 hr
n	4	6	4	4	6	4
Km	6.31 ± 3.83	1.88 ± 0.98	1.38 ± 0.73	6.14 ± 4.45	3.76 ± 1.83	1.52 ± 0.34
Vmax	24.75 ± 12.57	24.0 ± 12.0	153.3 ± 44.4*	34.3 ± 20.5	38.5 ± 25.0	97.6 ± 45.9*
a	0.66 ± 0.99	0.68 ± 0.72	3.1 e-08 ± 8.5 e-09	1.00 ± 1.14	0.58 ± 0.53	0.19 ± 0.37

All cells were cultured for a total of 24 hours in the presence of 150 μM ZnSO₄ for 4 or 24 hr or in its absence as indicated. Uptake of ³⁵S-BSP was assayed at 24 hr as described in Methods.

^*p <0.03 as compared to cells at 0 or 4 hours after Zn addition.