Figure 4

Lineweaver-Burk plot of mutual inhibitory effects on uptakes of diphenhydramine or [³H]pyrilamine by hCMEC/D3 cells. Diphenhydramine uptake was measured at 37°C for 15 sec in the presence (●) or absence (○) of pyrilamine (150 μM) (A) or oxycodone (500 μM) (C). [³H]Pyrilamine uptake was also measured at 37°C for 10 sec in the presence (●) or absence (○) of diphenhydramine (50 μM) (B). Each point represents the mean ± S.E. of four determinations.