Figure 5.

Meth- and Se-induced changes in total GSH (tGSH) content and oxidized GSH (GSSG) fraction. tGSH and GSSG were measured in lysates and media from SH-SY5Y cells differentiated in media containing 10 nM Se for 2 weeks followed by either a 0, 10, or 100 nM Se for 1 week, and then treated with or without 100 μM Meth for 24 hrs. A. Intracellular tGSH is decreased at 100 nM relative to 0 and 10 nM Se without Meth. Addition of 100 μM Meth decreases tGSH at 0 and 10 nM Se. B. The ratio of intracellular GSSG to tGSH is increased by addition of 100 μM Meth at 10 nM and 100 nm Se. Two-way ANOVA and Bonferroni post hoc test were used. Samples from three replicate cultures were used, with four assays averaged for each sample. C. Extracellular tGSH is increased in media containing 0 nM Se. Horizontal line indicates the amount of GSH originally added to the media (3.6 μM). D. The ratio of extracellular GSSG to tGSH in unchanged by Se content of media or addition of Meth. Bars show mean ± SEM for four replicate cultures per condition. Total **** indicates p<0.0001, *** indicates p<0.001, ** indicates p<0.01, * indicates p<0.05.