TABLE 3

Uptake clearance of digoxin and CCK-8 in human hepatocyte suspensions and day 5 sandwich culture

[3H]CCK-8 was tested at 1 μM. [3H]Digoxin was tested at 1 and 0.05 μM in suspension and sandwich culture, respectively. Uptake clearance was determined over 0.5, 1, and 2 min in suspension, whereas uptake clearance in sandwich culture was determined at a single 5-min time point. Suspension data are presented as the mean of triplicate determinations from a single experiment (digoxin) or as the mean of two experiments each run in triplicate (CCK-8). Unless indicated, sandwich culture data represent the mean of triplicate determinations from a single experiment.

CompoundHepatocyte LotUptake Clearance
SuspensionDay 5 SCHH
Vehiclea+100 μM Rifamycin SV
μl/(min · mg protein)
Digoxin1093.704.061.88b–3.08c
Hu41654.154.533.60
CCK-8Hu41652.440.351.06
  • a Vehicle = 0.11% dimethyl sulfoxide.

  • b Determined from Vmax/Km (Fig. 2).

  • c Mean of 8 separate studies (S.E. = 0.26) (Table 1).