Fig. 5.

Permeability of drugs and endogenous nutrients in three-dimensional blood–brain barrier (3D-BBB) system under same conditions without inhibitor. Transcellular transport of drugs and endogenous nutrients in the capillary lane (A-side) and brain lane (B-side) across brain microvascular endothelial cells derived from human induced pluripotent stem cells (hiPS-BMECs). The directional transport of quinidine, atenolol (a, b; P-gp substrate), dantrolene, cladribine (c, d; BCRP substrate), [³H] L-arginine (e; CAT1 substrate), [³H] L-glutamate (f; GLAST substrate), [¹⁴C] L-lactate (g-i; MCT1 substrate), and gabapentin (j; LAT1 substrate) was measured for up to 2 or 4 h. Open and closed circles show transport in the A-to-B (capillary lane-to-brain lane) and B-to-A (brain lane-to-capillary lane) directions, respectively. The transport of [¹⁴C] L-lactate was performed at pH 7.4, for both the capillary and brain lanes (g), at pH 6.0 for the capillary lane (h), and at pH 6.0 for the brain lane (i). Each value represents the mean ± standard error of 4–8 experiments.