Figure 4.
A, Effect of treatment with the superoxide dismutase mimetic M40403 and the H2O2-decomposing agent polyethylene glycol catalase (PEG-CAT) on responses to 4-aminopyridine (4-AP) in arteries from normoxic and hypoxic piglets of the 3-day exposure group (for normoxic arteries: 
untreated arteries and 
M40403+PEG-CAT-treated arteries; for hypoxic arteries: 
untreated arteries and 
M40403+PEG-CAT-treated arteries). B, Effect of treatment with the NADPH oxidase inhibitor apocynin on responses to 4-AP in arteries from normoxic and hypoxic piglets of the 3-day exposure group (for normoxic arteries: 
untreated arteries and 
apocynin-treated arteries; for hypoxic arteries: 
for untreated arteries and 
apocynin-treated arteries). In both panels, all values are mean ± SEM, and an asterisk indicates a significant difference from untreated normoxic arteries (
).