Figure 4. Effect of inhibitory drugs on quinacrine accumulation by dermal fibroblasts.
(A) Concentration-effect relationship for bafilomycin- and monensin-induced suppression of quinacrine uptake (1 µM, 2 h) by mouse dermal fibroblasts. Presentation as in Fig. 3A. Experimental values were compared using ANOVA (P < 10−4) followed by Dunnett’s test to compare each value from inhibitor-treated cells with the control uptake value without inhibitor (the effect of all concentrations of either inhibitor was significant, P < 0.01). (B) Effect of the P-glycoprotein inhibitor elacridar, of the OCT-1 to −3 inhibitor decynium-22 and of bafilomycin A1 on acute (30 min) quinacrine accumulation by fibroblasts (inhibitory drugs were applied 30 min before quinacrine). Values are means ± SEM of the number of determinations indicated between parentheses. (C) Effect of “promiscuous” transport inhibitors (concentrations as indicated) on quinacrine uptake by fibroblasts (same protocol as in B). Presentation as in (B).