Figure 1.

ABCB1 transport activity at the BBB measured with (R)-[¹¹C]verapamil PET imaging. Brain uptake of (R)-[¹¹C]verapamil expressed as brain-to-blood radioactivity concentration ratio (K_b,brain) at 60 min after radiotracer injection in female C57BL/6 mice (veh: n = 6, tariquidar: n = 5), hABCB1 mice (genOway; veh: n = 3, tariquidar: n = 3), and hABCB1 mice (Taconic; veh: n = 4, tariquidar: n = 3) treated with vehicle solution (2.5% [w/v] aq. dextrose solution) or tariquidar (15 mg/kg body weight) at 2 h before radiotracer injection. For comparison, K_b,brain in vehicle-treated Abcb1a/b^(–/–) mice (n = 4) is also shown [36]. Data are mean ± standard deviation. Statistical significance was determined by 2-way ANOVA with Bonferroni post-hoc test. **p < 0.01; ***p < 0.001