Intracellular ROS increase before formation of atherosclerotic lesions in hyperlipidemic mice Female <i>Apoe</i>^-/- mice were fed either chow diet or Western diet.

<p><i>(A)</i> The descending thoracic aorta (delineated by dashed line) was relatively spared from atherosclerosis, even in mice fed Western diet. <i>(B)</i> In the descending thoracic aorta, Western diet increased extracellular ROS before formation of atherosclerotic lesions <i>(C)</i> Extracellular ROS levels, in contrast, were increased after formation of atherosclerotic lesions. n = 6–7 in each group. *p>0.05 vs chow diet, One way ANOVA with Dunnett’s multiple comparison test.