Fig. 5.

Apical [³H]choline uptake in cultured choroid plexus epithelial cells exposed to cadmium in serum-free medium with the MEK1 inhibitor, PD98059. Cells were incubated in serum-free medium for 12 h; during the last 2 h, cells were treated with 0 or 25 μM PD98059. Cells then were exposed for 12-h to 0 or 500 nM CdCl₂ with 0 or 25 μM PD98059. After treatment, cells were rinsed and incubated (37°C, 30 min) in artificial CSF with 10 μM [³H]choline ± 750 μM hemicholinium-3; transport buffer did not contain cadmium or PD98059. [³H]Choline uptake was expressed as a percentage of mediated uptake in control cells incubated for 24 h in serum-free medium without cadmium or PD98059. Values are expressed as means ± SE; n = 3 separate culture preparations. *Significantly different than nontreated controls (No Cd/No PD98059); P < 0.05.