Figure 2.

Glutathione homeostasis and detoxification enzyme activities in WT and PK-KO glial cultures. Glial cultures at 20–30 DIV were assayed for glutathione levels, γ-glutamylcysteine synthetase mRNA, and detoxification enzyme activities. A, Intracellular glutathione content, expressed as nanograms of GSH per microgram of protein. B, γ-GCS mRNA levels in WT and PK-KO glial cultures. C, Specific activities of GPx and catalase enzymes. D, GST activity in WT and PK-KO glial cultures. The activities of the detoxification enzymes were normalized to the total protein content. Values are the mean ± SEM of two or four independent cultures with six replicates each. Statistical analysis was performed by one-way ANOVA, followed by Newman–Keuls multiple comparison test. ⁺p < 0.05; ⁺⁺p < 0.01, PK-KO versus WT cultures.