Figure 5: Caspase-3 expression and apoptosis in penile tissues. (a) The expression of caspase-3 and cleaved caspase-3 detected with Western blot. (b) Relative density of caspase-3 and cleaved caspase-3 compared with β-actin. Data are shown as the fold changes over the control group. n = 4 for each group. (c) Caspase-3 activity detected with a caspase-3 activity assay kit and normalized by the protein concentration. n = 3 for each group. (d) Apoptosis detected with terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling staining (×200). Apoptotic cells were stained in brown. (e) Apoptosis index in the corpus cavernosum. n = 3 for each group. Statistical analyses were conducted using one-way analysis of variance followed by the Tukey test. *P < 0.05, compared with control group. #P < 0.05, compared with DM group. DM: diabetes mellitus.