FIG. 7.

ONOO⁻ scavenger and antioxidant attenuates high glucose–induced GTPCH1 degradation via endogenous ONOO⁻ in endothelial cells. A: UA (100 μmol/L) or Tempo (10 μmol/L) prevented GTPCH1 degradation. BAECs were pretreated with UA or Tempo for 30 min and treated with normal-glucose (NG) medium (d-glucose, 5 mmol/L) or high glucose (HG) (d-glucose, 30 mmol/L) for 3 days. B: GTPCH1 activity. n = 3. C: Adenoviral (AD) overexpression of Mn-SOD prevents GTPCH1 degradation. BAECs were transformed with adenoviral vector GFP or Mn-SOD for 16 h and treated as indicated for 3 days. D: L-NAME (1 mmol/L) prevents GTPCH1 reduction. The blot shown is representative of three independent experiments. NS, not significant. *P < 0.05 vs. NG control; **P < 0.05 30 mmol/L plus UA vs. 30 mmol/L HG; #P < 0.05 30 mmol/L plus Tempo vs. 30 mmol/L HG.