Human Tissue Kallikrein 1 Improves Erectile Dysfunction of Streptozotocin-Induced Diabetic Rats by Inhibition of Excessive Oxidative Stress and Activation of the PI3K/AKT/eNOS Pathway

Figure 4

hKLK1 could inhibit oxidative stress and apoptosis in the corpus cavernosum of diabetic rats. Panels (a) and (b) show protein expressions of RAGE, NOX2, p67^phox, and p47^phox normalized to β-actin level. Panels (c) and (d) show MDA level and SOD activity normalized to total protein concentration of penile samples. Panels (e) and (f) show protein expressions of Caspase3 and cleaved Caspase3 normalized to β-actin level. Panel (g) shows the ratio of Bax/Bcl-2 in different groups. Apoptosis levels were assayed by the terminal deoxynucleotidyl transferase-mediated nick end labeling method (h, magnification: ×400). Panel (i) shows the calculated apoptosis index (percentage of apoptotic cells [brown stained] to all stained cells), which was used to quantify cavernous apoptosis level. Panel (j) shows the expressions of CD31 and α-SMA through immunohistochemical staining in all groups of penile tissues (magnification: ×100). Panels (k) and (l) show the positive area (%) of CD31 and α-SMA, respectively. Each bar represents . , , and . hKLK1: human tissue kallikrein 1; MDA: malondialdehyde; SOD: superoxide dismutase. WTR: wild-type rats; TGR: transgenic rats; WTDM: diabetic wild-type rats; TGDM: diabetic transgenic rats; TGDMH: diabetic transgenic rats administrated with HOE140.

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