Figure 1.

Schematic outlines for experimental treatments of choroid plexus epithelial cells (CPECs) or isolated choroid plexus (CP) tissues with cadmium (Cd), Zinc (Zn), and l-buthionine sulfoximine (BSO). (A) CPECs were incubated (48 h) in maintenance medium with 0 or 25 µM ZnCl₂ to prepare non-supplemented versus Zn-supplemented cells, respectively. Non-supplemented cells were then pretreated (12 h) in serum-free medium (SFM) before 12 h exposure in SFM to either 0 or 500 nM CdCl₂; Zn-supplemented cells were pretreated (12 h) in SFM with 10 µM ZnCl₂ before 12 h exposure in SFM with 10 µM ZnCl₂ and either 0 or 500 nM CdCl₂. (B) Non-supplemented CPECs were prepared and pre-treated (12 h, SFM) before 12 h exposure in SFM with either 0 or 500 nM CdCl₂; cadmium and time-matched control cells were collected at 3, 6, 9, and 12 h. (C) CP tissues from neonatal rats were isolated and incubated (24 h) in SFM with 0 or 500 nM CdCl₂. (D) Non-supplemented CPECs were prepared and then incubated (24 h, SFM) with 0-100 µM ZnCl₂. (E) Non-supplemented and Zn-supplemented CPECs were prepared and exposed to cadmium in the absence or presence of BSO, an inhibitor of glutathione synthesis. Representative non-supplemented and Zn-supplemented cells were treated (12 h) in SFM without or with 10 µM ZnCl₂ respectively, but not subjected to further treatment. Other cells were treated as follows. In absence of BSO, a group of non-supplemented cells was pre-treated (12 h, SFM) and then exposed (12 h) in SFM to either 0 or 500 nM CdCl₂. In absence of BSO as well, a group of Zn-supplemented cells was pre-treated (12 h, SFM) with 10 µM ZnCl₂ and then exposed (12 h) in SFM with 10 µM ZnCl₂ to either 0 or 500 nM CdCl₂. In the presence of BSO, another group of non-supplemented cells was pre-treated (12 h) in SFM with 100 µM BSO and then exposed (12 h) in SFM with 100 µM BSO to either 0 or 500 nM CdCl₂. In the presence of BSO as well, a group of Zn-supplemented cells was pre-treated (12 h) in SFM with 100 µM BSO and 10 µM ZnCl₂ and then exposed (12 h) in SFM with 100 µM BSO and 10 µM ZnCl₂ with either 0 or 500 nM CdCl₂. All treatments were performed at 37 °C.