ER-α signaling suppresses PPAR-γ mediated TBBPA induction of P-gp transport. A, 1 nM E2 blocks TBBPA induction of P-gp transport in male rat brain capillaries. B, Antagonizing ER-α signaling with 10 nM ICI blocks TBBPA mediated decreases in female rat brain capillaries. Graphs are mean fluorescence ± SEM for 10–20 capillaries from single preparation (pooled brains from 3 to 5 rats, 15–20 weeks old). ***p < .001, significantly different than control. Abbreviations: P-gp, P-glycoprotein; TBBPA, tetrabromobisphenol A.