Oxytocin immunoreactivity in the corpus cavernosum of patients with erectile dysfunction

Oxytocin is released by the posterior pituitary gland during male orgasm. Additionally, the presence of an oxytocin receptor gene and protein expression in human corpus cavernosum is demonstrated, and it has contractile activity on the smooth muscle of the animal and human corpus cavernosum in vitro. The aim of this study was to investigate the immunoreactivity of oxytocin in corpus cavernosum of patients with organic erectile dysfunction and to compare it with healthy controls.

Cavernous biopsies were obtained from 31 patients with erectile dysfunction and 11 patients without erectile dysfunction. Oxytocin immunohistochemistry was performed using the streptavidin-biotin immunoperoxidase staining on all cases. Intensity and proportion of stained cells were added for the immunoreactivity score.

The mean ages of patients with erectile dysfunction and controls were 41.47 ± 2.08 and 36.50 ± 3.35 years, respectively (p > 0.05). Oxytocin expression was detected in smooth muscle as well as in endothelial cells in both groups. The mean oxytocin immunoreactivity score values of patients with erectile dysfunction and controls were also 2.16 ± 0.12 and 2.30 ± 0.21, respectively (p > 0.05). There was no significant difference in immunoreactivity scores both in arterial and cavernosal failure and also in smoker and nonsmoker groups (p > 0.05). Immunoreactivity scores were not statistically significantly different between patients with concomitant medical disorders and patients with no other medical disorder (p > 0.05).

We detected oxytocin immunoreactivity in male corpus cavernosum, but staining was not different between patients with erectile dysfunction and controls. However, further studies are necessary to reach a final conclusion regarding the effects of oxytocin on corpus cavernosum.