Potency of MDPV, α-PVP, and MDPPP in inhibiting the activity of hDAT, wt dDAT, and the triple and quadruple dDAT mutants. Stable cell lines expressing the indicated transporters were transfected with CaV1.2 and auxiliary subunits. Intracellular Ca2+ signals were determined using fluorescence microscopy under constant perfusion at 35°C in Fura2-AM loaded cells. A) Dose-response curves of the inhibitory effect that MDPV has at the A117S/D121G/P323V dDAT and A117S/D121G/P323V/F318C dDAT mutants. The curves for MDPV at hDAT and wt dDAT shown in Fig. 1C are included in the graph for reference (dashed lines). Each data point represents the mean ± SEM of N ≥ 60 cells analyzed per concentration. B) Dose-response curves of the inhibitory effect of α-PVP at hDAT, wt dDAT, and A117S/D121G/P323V dDAT and A117S/D121G/P323V/F318C dDAT mutants. Each data point represents the mean ± SEM of N ≥ 66 cells analyzed per concentration. C) Dose-response curves of the inhibitory effect of MDPPP at hDAT, wt dDAT, and A117S/D121G/P323V dDAT and A117S/D121G/P323V/F318C dDAT mutants. Each data point represents the mean ± SEM of N ≥ 53 cells analyzed per concentration. The pIC50 values are described in Table 2.