Figure 4.

Absence of NADPH oxidase-1 (NOX1) decreased reactive oxygen species generation induced by hyperoxia in primary pulmonary type II alveolar epithelial cells (AECs) and in mouse lung endothelial cells (MLECs). (A) Isolated type II AECs and (B) MLECs from NOX1^−/−, NOX2^−/−, and wild-type (WT) mice were exposed to hyperoxia for 24 hours and loaded with dihydroethidium (DHE, 5 μM) and visualized by confocal microscopy (pseudocolor). Original magnification, ×100. (C and D) Quantification of DHE fluorescence intensity of type II AECs and MLECs. Values represent means and SEM (n = 3 mice for each group; ^†††P < 0.001, NOX1^−/− vs. WT mice in hyperoxia; and P = not significant [NS], NOX2^−/− vs. WT mice in hyperoxia).