Fig. 7.
Representative section of lung incubated with dihydroethidium (DHE) and imaged using fluorescence microscopy following resuscitation (Res) with 21% oxygen (A) or 100% oxygen (B). Conversion of DHE by superoxide to ethidium results in red nuclear fluorescence. Fluorescent intensity of each image (n = 6 in each group) was quantified using Metamorph imaging software. Following resuscitation with 100% oxygen, pulmonary arterial fluorescence was 2.24 ± 0.46 times higher than resuscitation with 21% oxygen. PA, pulmonary artery; AW, airway. C: force of contraction of 5th generation pulmonary arterial rings to norepinephrine (10−8 to 10−6 M). Contraction responses following incubation with polyethylene glycol-conjugated superoxide dismutase (SOD) and catalase (CAT) are shown as dashed lines. ‡P < 0.05, compared with 21% Res by ANOVA repeated measures.