Figure 4: Detection of fibrosis by Masson's trichrome staining, cavernous α-SMA immunohistochemical staining and western blot. (a) Masson's trichrome staining; (b) bar graph of smooth muscle/collagen; (c) cavernous α-SMA immunohistochemical staining; (d) bar graph of cavernous α-SMA immunohistochemical staining; (e) the expression of TGF-β1 in corpus cavernosum of Western blot; (f) bar graph of the expression of TGF-β1 in corpus cavernosum. Scale bars = 50 μm; n = 6 in each group. Representative micrographs of Masson's trichrome staining show smooth muscle component as red areas, collagen component as blue areas (×200). Representative micrographs of cavernous α-SMA immunohistochemical staining show penile smooth muscle alpha-actin as brown areas (×200). Data of western blot analysis are shown as the fold changes over the control group. Bar graphs represent mean ± standard deviation. *P < 0.05 and **P < 0.01, the indicated group compared with the Sham group; #P < 0.05 and ##P < 0.01, the indicated group compared with the BCNI group. α-SMA: alpha smooth muscle actin; BCNI: bilateral cavernous nerve injury; TGF-β1: transforming growth factor beta 1.