fig3

Figure 3. Intracellular cytotoxic drug accumulation. Radiolabeled drugs, including 4 µmol/L [³H]-daunorubicin (A), 50 nmol/L [³H]-vinblastine (B), and 10 mmol/L [³H]-etoposide (C), were incubated with R7, RVC and RDC cells in the presence or absence of cyclosporine (CsA, 4 µmol/L), PSC-833 (PSC, 2 µmol/L), and verapamil (VER, 6 µmol/L). Measurements of the intracellular radiolabeled drugs were performed as described in Materials and Methods. The mean values (columns), also labeled on the top of the histograms, and standard deviations (bars) are derived from quadruplicate determinations. One of two similar experiments is shown