Figure 2.

Inhibitory effects of colistin and polymyxin B on the substrate uptake mediated through 15 essential SLC transporters that were overexpressed by HEK293 cells. Uptake of each radiolabelled substrate was measured in the absence (black bars) and presence of 10 µM colistin (light grey bars) or polymyxin B (dark grey bars) in cells overexpressing human (a) OAT1, OAT2, OAT3 and OAT4; (b) OATP1A2, OATP1B1, OATP1B3 and OATP2B1; (c) OCT1, OCT2, OCT3, OCTN1 and OCTN2; and (d) PEPT1 and PEPT2. Background counts of vector-transfected cells were subtracted from all uptake data and the standardized result is presented as a percentage of the control (i.e. no inhibitors). In all experiments, experiments were conducted independently three times with three replicates in each experiment and values are expressed as the mean ± SEM. Significant difference from the control: *P < 0.05 and **P < 0.01.