Figure 3.

Glutamate accumulation and glutamate transporter function under hypoxic conditions after IL-1β pretreatment. Mixed cortical cell cultures were treated with 1 ng/ml IL-1β for 20–24 h (black bars) or vehicle (hatched bars), washed, and then deprived of oxygen. A, After the period of time indicated, supernatant was collected to measure accumulation of glutamate in the bathing medium via HPLC. Data are expressed as the mean ± SEM glutamate accumulation in micromolar. An asterisk denotes a significant between group difference as assessed by two-way ANOVA followed by a Bonferroni's post hoc test (p < 0.001; n = 8 cultures pooled from 3 different experiments). B, After the times indicated, cells were washed, and [³H]d-aspartate (0.1 μCi) was added in the presence of 50 μm nonradioactive d-aspartate. Uptake was terminated after 5 min, and the amount of [³H]d-aspartate that accumulated into cells was measured via liquid scintillation counting. Data are expressed as mean ± SEM counts per minute per well per 5 min × 10³. There was no statistically significant between-group difference in [³H]d-aspartate uptake as determined by two-way ANOVA. An asterisk indicates a significant decrease in [³H]d-aspartate uptake from the 30 min time point within each group as determined by two-way ANOVA followed by a Bonferroni's post hoc test for multiple comparisons. Significance was assessed at p < 0.05 (n = 8 cultures pooled from four different experiments).