Dihydroethidium (DHE) fluorescence in PRAs in untreated lung sections and lung sections treated with M40403 from piglets raised in normoxic or hypoxic conditions for 3 days (A; n = 5 each in untreated control, M40403-treated control, untreated hypoxic, and M40403-treated hypoxic groups) or 10 days (B; n = 5 each in untreated control, M40403-treated control, hypoxic, and M40403-treated hypoxic groups). Values are means ± SE.