Table 2.

Effects of Zinc supplementation on glutathione (GSH) and glutathione sulfide (GSSG) concentrations and GSH:GSSG ratio in choroid plexus epithelial cells (CPECs) exposed to 500 nM CdCl₂ for 12 h.

Condition	GSH, µM	GSSG, µM	GSH:GSSG Ratio
Control	5.20 ± 0.50	0.029 ± 0.010	318.4 ± 102.99
Cd	9.18 ± 0.27 *	0.207 ± 0.023 *	43.28 ± 5.89 *
Zn	5.25 ± 0.46	0.035 ± 0.010	273.73 ± 99.76
Zn + Cd	7.84 ± 0.87 *	0.121 ± 0.022 *	71.94 ± 14.97 *

CPECs were first incubated for 48 h in maintenance medium without Zinc; i.e., non-supplemented cells, or with 25 µM ZnCl₂; i.e., Zn-supplemented cells. Non-supplemented cells were pre-treated (12 h) in serum-free medium (SFM) and then divided into two sets: one set was exposed for 12 h in SFM (Control), while the other was exposed for 12 h to 500 nM CdCl₂ in SFM (Cd). In parallel, Zn-supplemented cells were pre-treated (12 h) in SFM with 10 µM ZnCl₂ and then divided into two sets: one set was exposed for 12 h in SFM with 10 µM ZnCl₂ (Zn), while the other was exposed for 12 h to 500 nM CdCl₂ in SFM with 10 µM ZnCl₂ (Zn + Cd). All incubations were at 37 °C. GSH and GSSG were analyzed by luminescence in triplicate in four different culture preparations (n = 4); GSH:GSSG ratios were calculated. Data are means ± SE; n = 4 culture preparations. * p < 0.05 vs. Control.