TABLE 1

Gene knockdown of OATP1B1 or BCRP significantly reduces the Vmax of the transporter without affecting its Km

Overexpressed Transporter Cell LinesKinetic ParametersControl CellsaGene Knockdown CellsP valueb
OATP1B1 (CHO cells)Vmax (fmole/min/mg protein)4583.6 ± 464369 ± 192<.001
Km (µM)4.06 ± 1.034.48 ± 1.44.71
BCRP (MDCKII cells)Vmax (AU/min/40,000 cells)31.9 ± 3.3124.8 ± 1.95<.05
Km (µM)3.45 ± 1.103.76 ± 0.89.72

  • AU, arbitrary fluorescence unit.

  • ↵a Cells transduced with control (scrambled shRNA).

  • ↵b Unpaired t test.