Fig. 5. Heme-binding protein 1 (Hebp1) decreases corpus cavernosum reactive oxygen species production in mice with streptozotocin (STZ)-induced diabetes. (A, B) In situ detection of superoxide anion (A, hydroethidine, red) and nitrotyrosine (B, red) production in corpus cavernosum endothelial cells (A and B, green) from age-matched control mice and mice with STZ-induced diabetes stimulated at 2 weeks after intracavernous injection of PBS (20 µL) or Hebp1 (1 µg/20 µL and 5 µg/20 µL). Nuclei were labeled with DAPI (blue). Scale bars, 100 µm. (C, D) The ethidium bromide fluorescence-immunopositive cavernosum area and nitrotyrosine-immunopositive cavernosum area were quantified by use of ImageJ software (n=4). ^***p<0.001. The relative ratio of the control group was arbitrarily set to 1. DM, diabetes mellitus; ns, not significant.