Fig 4.

(A). Superoxide anion release in mesenteric segments from control and four- (4W) and eight-week (8W) diabetic rats. Results (mean ± S.E.M.) are expressed as chemiluminiscence units (U)/min mg tissue. (B). Effect of four and eight weeks’ diabetes on peroxynitrite formation in rat mesenteric arteries. Results (mean ± S.E.M.) are expressed as arbitrary units (A.U)/min mg tissue. N = 5–7 animals each group. (C). Superoxide dismutase activity in mesenteric arteries from control and four- and eight-week diabetic rats. Results (mean ± S.E.M.) are expressed as arbitrary units (A.U)/min μg tissue. (D). Effect of four and eight weeks’ diabetes on Cu-Zn superoxide dismutase (SOD) expression. Lower panel shows relation between Cu-Zn SOD expression and β-actin. Results (mean ± S.E.M.) are expressed as ratio of the signal obtained for each protein and the signal obtained for β-actin.