Characterization of Cu,Zn-SOD–/– mice. (a) Western blot analysis for SOD isoforms in mesenteric arteries from control (WT) and Cu,Zn-SOD–/– (KO) mice. Cu,Zn-SOD expression was absent in the Cu,Zn-SOD–/– mice, whereas the expression of MnSOD and ecSOD was unaltered. (b) Cu,Zn-SOD activity of mesenteric arteries from the two strains. Cu,Zn-SOD activity was absent in the Cu,Zn-SOD–/– mice. Comparable activities of glutathione peroxidase (c) and catalase (d) of the liver in the two strains (n = 5 each). (e) Western blot analysis for eNOS expression in mesenteric arteries (n = 5 each). eNOS protein expression was comparable between the two strains.