Effects of oxytocin on sperm transport in the pubertal rat

Abstract

Oxytocin is present in the mammalian testis where it increases contractility of seminiferous tubules in vitro and has been implicated in sperm transport. The

A Neuropeptide in Human Semen: Oxytocin

“…OT is not only produced in Leydig cells but also in seminiferous tubuli [ 113. One of its effects is thought to be the enhancement of spermiation and of the subsequent transport to the epididymis [4]. The similarity of OT levels in all groups in our study suggests that subjects with poor sperm quality are not additionally "handicapped" by an irregular transport to the epididymis.…”

“…Based on these observations it may be speculated that OT plays a role in spermatogenesis. Recently, it was found that OT enhanced the transport of spermatozoa from the testes to the epididymis in the rat after subcutaneous administration [4]. Moreover, OT was found to increase the percentage of motile spermatozoa and sperm velocity in in vitro experiments using bull spermatozoa [6].…”

Spermiation

“…88 These observations confirm previous studies suggesting a role for oxytocin in spermiation and sperm transport. 86 Oxytocin may regulate spermiation by specific intracellular signaling pathways leading to release, and/or by influencing seminiferous tubule contractility or fluid production which in turn modulates spermatid release and their subsequent transport to the epididymis.…”

Oxytocin: recent developments

“…Spermiation is delayed in oxytocin null mice but is accelerated in mice overexpressing oxytocin (68). Similarly, the arrival of sperm in the epididymis can also be increased by oxytocin in the rat by increasing tubular transport and spermiation (69). Oxytocin also increases sperm movement through the epididymis by increasing spontaneous contractile activity (70).…”

“…In animals, oxytocin can increase semen volume and number of ejaculated sperm in rams (124), induce shedding of spermatozoa from the seminiferous tubules and induce sperm movement through the reproductive tract of rats, mice and rabbits (68,69,125). Furthermore, the peak of oxytocin at orgasm is highly suggestive that oxytocin contributes to ejaculation in humans (38,72).…”