Fig. 3

Masson’s trichrome staining and immunohistochemical staining. a Penis samples are prepared for the detection of corpus cavernosum tissue fibrosis using Masson’s trichrome staining (magnification × 100). The smooth muscle components appeared red colour. The collagen components appear blue colour. Bar = 25 μm. b Immunohistochemical staining for α-SMA as brown areas, which stains smooth muscle cell(SMC) in the corpus cavernosum (magnification × 200). Bar = 50 μm. c Immunohistochemical staining for caspase-3 as brown areas, which stains SMCs apoptosis in the corpus cavernosum(magnification × 200). Bar = 50 μm. d Semiquantitative image analysis of muscle/collagen ratio in corpus cavernosum tissues was performed using GraphPad Prism 5.0 soft. e Semiquantitative image analysis of α-SMA expression in corpus cavernosum. f Apoptotic index presented as the ratio of apoptotic SMCs (expression of caspase-3) to the total SMCs in corpus cavernosum. Values are presented mean ± standard deviation of the mean and the differences among groups are analysed using one-way ANOVA; +P < 0.001 vs. the Control group; *P < 0.05, **P < 0.01, and ***P < 0.001 vs. the ED group; ## P < 0.01 and ### P < 0.001 vs. the INS group. Control = normal control, ED = diabetes-related erectile dysfunction, INS = insulin treatment, IT = islet transplantation