Figure 4. Effect of oxidative stress on the activity of P-gp in mitochondria of D407 cells.

D407 cells were treated with 200 µmol/L H₂O₂ alone or in combination with 1 µmol/L of tariquidar (1h prior to H₂O₂ treatment) for up to 24h. Untreated cells were set as the control (CTL). The activity of P-gp was determined by measuring the intracellular Rho-123 fluorescence intensity using flow cytometry. Data are the mean±SE of three separate experiments. ^aP<0.05.