Fig. 4

In NOX2-null mice, connexin levels in atrium and in ventricle are not affected by exposure to intermittent hypoxia. Homogenates were prepared from atria (a, b) or ventricles (c) of NOX2-null mice exposed to room air (RA) or exposed to intermittent hypoxia (IH). Cx40 (a) and Cx43 (b, c) were detected by immunoblotting. Gels were loaded with equal amounts of total protein (10 μg for A, 1 μg for B,C) and were also blotted with antibodies directed against vinculin (as a loading control). Graphs show the amounts (mean ± SEM) of immunoreactive connexin in control (RA) and IH mice determined by densitometry (adjusted for vinculin and normalized to the mean control values). Representative blots are shown on the right. The abundances of Cx40 and Cx43 did not differ significantly between RA (black bars) and IH groups (grey bars; p > 0.05, Student’s t test). n = 3 for atrium; n = 3 for ventricle)