Isoproterenol Induces Vascular Oxidative Stress and Endothelial Dysfunction via a Giα-Coupled β2-Adrenoceptor Signaling Pathway
Figure 6
Giα protein activity mediates the vascular oxidative stress induced by isoproterenol.
Panel A shows representative fluorographs of microscopic sections of thoracic aorta from wild-type (WT) and β2KO mice treated for 7 days with vehicle or isoproterenol (ISO). Vessels were labeled with the oxidative dye hydroethidine, which produces a red fluorescence when oxidized to ethidium bromide. Panel B shows the densitometric analysis of the ethidium-bromide-positive nuclei evaluated under basal conditions or incubated with apocynin (APO, 30 μM), L-NAME (LN, 100 μM), PTx (4 μM) or superoxide dismutase (SOD, 150 U/mL). The fluorescence signal was evaluated as the intensity of fluorescence per pixel normalized by vessel area. Values are presented as the mean ± SEM. N = 4–7 animals in each group. Significance was assessed using a 2-way ANOVA: *p<0.05 vs. respective basal values for each group; #p<0.05 vs. basal WT value; +p<0.05 vs. ISO-treated WT value.