Fig. 8.

Cocaine Decreases BCRP, MRP4, and P-gp Transport Activity. Endothelial cells were loaded with dyes specific for A BCRP (Hoechst 33,342, 5 µg/mL), B MRP4 (monobromobimane, 10 μM), and C P-gp (rhodamine 123, 10 μM) for 1 h (grey) and the dyes allowed to efflux out of the cell for four hours following pre-treatment with cocaine (10 μM, burgundy) or vehicle (teal). The cells were also pre-treated with specific inhibitors of (A) BCRP (10 μM, fumitremorgin), B MRP4 (10 μM, ceefourin 1), C P-gp (10 μM, ritonavir) (yellow) or PXR (resveratrol, 10 μM, lavender). Flow cytometric analysis was performed to evaluate the fluorescence and one histogram, representative of five independent experiments is shown (left). The fluorescent signal from flow cytometry was determined for endothelial cells pre-treated with cocaine (10 μM, burgundy) or vehicle (teal). Five independent experiments (represented by individual dots) were performed. Estimation plots are shown where the left y-axis denotes the mean fluorescent intensity (MFI, pixels) for A Hoechst 33,342 B monobromobimane, and C rhodamine 123 and the right y-axis reflects the effect size (black bar), which is the difference between means of each condition (right). Data are represented as mean ± standard deviation. *p < 0.05. **p < 0.01. Paired T-test was performed