Figure 1. PDE5 expression in LV outflow tract tissue from patients with severe aortic stenosis.

(A) In cardiac tissue of control subjects, PDE5 expression was limited. In contrast, in AS patients, marked PDE5 immunoreactivity was present in scattered cardiac myocytes. (B) Double immunofluorescent staining of PDE5 (green) and desmin (red) confirmed protein expression in cardiac myocytes. Scale bars, 25 µm.