Figure 2.

Sildenafil reduces endomysial fibrosis in the mdx diaphragm. (A) Representative diaphragm sections stained with collagen I (top row) and fibronectin (bottom row) antibodies. Both collagen I and fibronectin are markers of fibrosis in dystrophin-deficient skeletal muscle. Sildenafil reduced both collagen I and fibronectin deposition around mdx diaphragm muscle fibres. (B) Representative western blot of global fibronectin protein expression in vehicle and sildenafil-treated mdx diaphragms. Mdx diaphragms exhibit high levels of fibronectin that are significantly decreased by sildenafil treatment. (C) Western blot quantitation of fibronectin protein levels. Sildenafil significantly reduced fibronectin expression in the mdx diaphragm. Scale bars in A: 100 μm (top row) and 50 μm (bottom row). Wild-type (n = 5); vehicle and sildenafil-treated mdx mice (n = 4 each).