Fig. 1

Connexin levels are reduced in homogenates of atrium (a, b) and of ventricle (c) in samples prepared from wild type C57BL/6 J mice exposed to intermittent hypoxia. Homogenates were prepared from atria (a, b) or ventricles (c) of mice exposed to room air (RA) or 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). Blots were also reacted 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 were significantly less in all IH groups (grey bars) as compared with corresponding RA controls (black bars; *, p < 0.05, Student’s t test, n = 6 for atrium; n = 9 for ventricle)