TABLE 2

Inhibitory effect of various compounds on the uptake of [³H]digoxin and [³H]CCK-8 in SCHH lot Hu4165

The uptake of 0.05 μM [³H]digoxin or 1 μM [³H]CCK-8 was measured at 37°C for 5 min in the presence and absence of inhibitors. The CCK-8 control value was 1.06 pmol/mg protein/min. Data are expressed as a percentage of the control values ± S.D. (n = 3). Statistical significance was determined using the Student's t test as described under Materials and Methods.

Inhibitors	Concentration	[³H]Digoxin	[³H]CCK-8
	μM	%Control	%Control
Control (0.1% DMSO)^{^a}		100 ± 3.1	100 ± 10.4
Control (1% DMSO)^{^b}		100 ± 7.0
Cyclosporine A	10	93.2 ± 9.2	16.0 ± 0.6^*
BSP	100	113 ± 4.4	11.8 ± 2.0^*
FCCP	50	63.8 ± 1.1^*	14.4 ± 0.3^*
Rifampicin	100	120 ± 1.3^*	26.7 ± 3.3^*
Digoxin	100	48.9 ± 1.3^*	29.0 ± 4.0^*
Digoxin (1% DMSO)	500	55.5 ± 3.6^*

DMSO, dimethyl sulfoxide.
↵* p < 0.01, significantly different from control.
↵a The digoxin control value was 0.18 pmol/(min · mg protein).
↵b The digoxin control value was 0.14 pmol/(min · mg protein).