Table 1

Vinblastine uptake kinetics for SPGP cells compared with that of LLCPK MDR1 and LLC-PK1 cells

Cell lineKmVmax
μM pmol/cell/h
LLC-PK128.2  ± 4.716.5  ± 1.7
LLCPK1 sis738.3  ± 5.311.9  ± 0.1
LLCPK MDR199.4  ± 14.08.6  ± 1.1

Each cell line was incubated with 0.5–200 μM [3H]vinblastine for 4 h. Subsequently, cells were washed and processed for cell-associated radioactivity as described underExperimental Procedures. Data are given as the mean ± S.D. obtained from multiple individual experimental points from two separate experiments. K m is the concentration that gives one-half of the maximal accumulation of vinblastine in the cells;V max is the maximal concentration of vinblastine accumulation in the cells.