Figure 4.

Induced ROS transients in lung venular capillaries. DCFH-DA (2.5 μM) was infused for the indicated durations. DCF fluorescence transients are shown following cessation of DCFH-DA infusion (a) and after a single bolus of H₂O₂ (20 μM) (b). Peak fluorescence increases above baseline are plotted against bolus concentration (c) (line drawn by linear regression; slope at P < 0.05; n = 5 for each point; mean ± SE). (d) Effect of catalase (1,000 U/ml) on DCF fluorescence. H₂O₂ (100 μM) was given as indicated. (e) Trace shows DCF fluorescence in the presence or absence of PEG-catalase (100 U/ml). Replicated three times.