FIGURE 7.
Effects of Tiron on SK channel expression and increased tyrosine nitration of SK channels in HG. A 24-h incubation with the cell-permeable O2⨪ scavenger Tiron (10 mm) attenuated the down-regulation of SK2 (A) and SK3 (B) by H2O2 (50 μm) in HL-1 cells cultured with HG and NG (n = 3). The abundance of tyrosine-nitrated SK2 (C) and SK3 (D) in HL-1 cells cultured with HG was increased by >5-fold (n = 3). * represents p < 0.05. In contrast, tyrosine-nitrated SK1 was not changed by culture with HG in these cells (n = 3, p not significant) (E). After treatment with Tiron, the abundance of tyrosine-nitrated SK2 and SK3 was significantly reduced in HL-1 cells cultured in HG (n = 3 for each; * represents p < 0.05 versus no Tiron treatment) (F). Error bars represent S.E.