Figure 6.

Increase in cystine transporter activity follows IL-1β treatment. Mixed cortical cell cultures were treated with 1 ng/ml IL-1β or vehicle for 20–24 h. A–D, Cells were then moved to the anaerobic chamber, washed into deoxygenated BSS₅, and deprived of oxygen for 0 min (A, C) or 90 min (B, D). Thereafter, cells were washed with HBSS, and ¹⁴C-l-cystine was added for 5 min. A, C, Data are expressed as ¹⁴C-l-cystine uptake in picomoles per minute per milligram protein. The asterisk indicates a significant between-group difference as determined by two-way ANOVA followed by a Bonferroni's post hoc test. Significance was assessed at p < 0.05 (n = 6 cultures pooled from 3 different experiments). C, D, V_max and K_m of ¹⁴C-l-cystine uptake in cultures were estimated using the Hanes–Woolf plot and are evident as 1/slope and −x-intercept, respectively. An asterisk indicates a significant increase from nontreated cultures (p < 0.05; n = 6 cultures pooled from 3 different experiments).