Figure 5.

CYP drug biotransformation is supported by resorufin and OXC metabolism in EPI‐ECs after GR silencing. A, Formation of resorufin is the highest when using EPI‐EC non‐siRNA. GR silencing resulted in decreased resorufin conversion comparable to that of control DIV‐BBB (HBMECs). B, Similar results were obtained when analyzing the abluminal compartment. C, OXC metabolism is increased in EPI‐EC non‐siRNA in the luminal side compared with EPI‐EC GR siRNAs and HBMECs. C1, A relative increase in OXC penetration across the BBB was observed in EPI‐EC GR siRNA and HBMECs compared with EPI‐EC non‐siRNA DIV‐BBB. C2, Elevated LiCBZ levels in the abluminal side of EPI‐EC non‐siRNA suggest that OXC is metabolized by a GR‐CYP pathway. Such metabolism is lower in EPI‐EC GR siRNA or HBMECs. D, The levels of resorufin positively correlated with the amount (micrograms per milliliter) of OXC metabolized. Results are expressed as mean ± SEM (by analysis of variance). Asterisks indicate P ≤ 0.05