Dantrolene na

Commercially available compounds were used in the studies. Substrates for P‐gp: loperamide HCl, quinidine, verapamil HCl, substrates for BCRP: dantrolene Na, 2‐amino‐1‐methyl‐6‐ phenylimidazo[4,5‐b] pyridine (PhIP), glyburide, and the permeability markers/non‐substrates: atenolol and minoxidil were acquired from Sigma‐Aldrich (St Louis, MO). Loperamide, quinidine, and verapamil were selected as the prototypical commercial substrates for P‐gp, dantrolene for BCRP substrate, glyburide as dual P‐gp and BCRP substrate, based upon extensive in‐house in vitro and in vivo studies as well as previously published chemical and genetic knockout studies. atenolol and minoxidil are non‐substrates and were used to monitor the tight junctions in epithelial cells of the rodent BBB. The P‐gp and BCRP dual inhibitor, elacridar, was also acquired from Sigma‐Aldrich. The P‐gp inhibitor, valspodar, was acquired from Sigma‐Aldrich and Tocris Bioscience (Minneapolis, MN). Transporter compound specificity has been a challenge, historically. Many compounds inhibit and/or are transported by numerous drug transporters and/or CYP enzymes. The substrates and inhibitors were selected based upon study design and in vitro and in vivo concentrations.