Increase in oxytocin secretion at ejaculation in male.

In this study changes in plasma oxytocin levels were determined before and after ejaculation in patients with abnormal spermatogenesis. Plasma oxytocin levels rose significantly after ejaculation (P < 0.001, n = 17). There was no obvious correlation between plasma oxytocin levels and sperm count, sperm motility or the number of abnormal forms. Oxytocin may play a role in the precipitation of ejaculation in males.