Plasma concentration-time profiles of paclitaxel after intravenous and oral administration with or without WK-X-34 and LY335979 pretreatment in mice. (A) Paclitaxel was intravenously injected into WT mice (▲) and mdr1a/1b KO mice (▵) at a dose of 5 mg/kg. (B) Paclitaxel was orally administered into WT mice and mdr1a/1b KO mice at a dose of 20 mg/kg. ●: portal plasma concentration in WT mice, ■: systemic plasma concentration in WT mice, ○: portal plasma concentration in mdr1a/1b KO mice, and □: systemic plasma concentration in mdr1a/1b KO mice. (C,D) Paclitaxel was orally administered into WT mice at a dose of 20 mg/kg, pretreated with 40 mg/kg WK-X-34 (C) or 60 mg/kg LY335979 (D). ●: portal plasma concentration, ■: systemic plasma concentration. Data are represented as mean ± S.D. (n = 3).