Excerpt of study published in J Am Coll Cardiol 2008;52:843-850: Oxidative stress is increased in atherosclerotic lesions and might play an important role in plaque progression and calcification.

Methods: Superoxide (dihydroethidium fluorescence and lucigenin-enhanced chemiluminescence), hydrogen peroxide (H2O2) (dichlorofluorescein fluorescence), and expression and activity of pro- and antioxidant enzymes were measured in normal valves from hearts not suitable for transplantation and in stenotic aortic valves that were removed during surgical valve replacement.

Conclusions: This study provides evidence that oxidative stress is increased in calcified regions of stenotic human aortic valves. Increased oxidative stress is due at least in part to reduction in expression and activity of antioxidant enzymes and perhaps to uncoupled NOS activity. Based on this, mechanisms of oxidative stress differ between stenotic aortic valves and atherosclerotic arteries.