Fig 5.

Transepithelial transport of danofloxacin (10 μM) in parent MDCK-II (A) and in their murine Abcg2- and human ABCG2-transduced derivatives (D and G) in the absence or presence of TCBZSO (15 μM) or TCBZSO₂ (15 μM). The experiment was started with the addition of danofloxacin to one compartment (basolateral or apical). After 2 and 4 h, the percentage of drug appearing in the opposite compartment was measured by HPLC and plotted. TCBZSO (B, E, and H) and TCBZSO₂ (C, F, and I) were present as indicated. Results are means, and error bars (sometimes smaller than the symbols) indicate SDs (n = 3). ●, translocation from the basolateral to the apical compartment; ○, translocation from the apical to the basolateral compartment. r represents the relative transport ratio (i.e., the apically directed translocation divided by the basolaterally directed translocation) at 4 h.