Relationships of Seminal Plasma Prolactin with Spermatozoal Characteristics and Fertilizing Capacity in Vitro

Abstract

Seminal plasma prolactin (PRL) levels were determined in 224 semen samples collected from fertile and suspected infertile men, and their relationships with spermatozoal characteristics and fertilizing capacity in vitro were evaluated. PRL concentrations were similar in normospermic and oligospermic samples, but were significantly lower in azoospermic samples. PRL concentrations were significantly higher in samples with high spermatozoal motility than in those with low spermatozoal motility. There were no significant differences in PRL concentrations between normal-morphology and abnormal-morphology samples, and between high-fertilizing capacity and low-fertilizing capacity samples. A low degree of positive correlation was observed between the PRL concentration and the spermatozoal motility. There were no significant correlations between the PRL levels, the other spermatozoal characteristics, and the spermatozoal fertilizing capacity in vitro.These findings indicate that the seminal plasma PRL levels are significantly depressed in azoospermic subjects and suggest that the seminal plasma PRL may play a role in the rnaintenance of spermatozoal motility. Whether there is a potential function of prolactin in semen on spermatozoal fertilizing capacity, however, cannot be inferred from the present study.

Identification of bovine prolactin in seminal fluid, and expression and localization of the prolactin receptor and prolactin-inducible protein in the testis and epididymis of bulls exposed to ergot alkaloids

“…Physiological concentrations of PRL stimulated metabolism in human spermatozoa in vitro [15] and exhibited putative effects on motility [16,17]. Prolactin has been reported to exert a prosurvival effect on sperm cells [18] as pharmacologic PRL concentrations of 500 ng/mL or greater significantly maintained sperm motility for 19 hours posttreatment as assessed by computer assisted semen analysis.…”

Seminal prolactin is associated with HSP90 transcript content in ejaculated spermatozoa

“…Our findings also indicated that there was no correlation between seminal PRL levels and sperm morphology. Similarly, Chan et al [ 11 ]. found that seminal levels of PRL did not differ between normozoospermic and teratozoospermic men.…”

“…Tang and Chan [ 30 ] reported that the seminal levels of PRL in azoospermic patients were significantly lower than in normozoospermic men. Moreover, Chan et al [ 11 ] found that seminal levels of PRL did not meaningfully differ between normozoospermic and oligozoospermic men, but were significantly lower in azoospermic men. They also reported that seminal PRL concentrations were higher in subjects with higher sperm motility.…”

“…Gonzales et al [ 33 ] demonstrated that seminal PRL concentrations had a significant positive correlation with sperm motility and were related negatively to sperm concentration. However, Chan et al [ 11 ] showed that there was no association between seminal levels of PRL and sperm parameters. Our findings also indicated that there was no correlation between seminal PRL levels and sperm morphology.…”

“…In addition, PRL is present in human seminal plasma [ 9 ] and has been shown to affect sperm metabolism [ 10 ] and motility [ 11 , 12 ]. It also exerts a prosurvival effect on spermatozoa cells mediated by the suppression of apoptosis, inhibits DNA strand breaks, and suppresses their entry into a state of capacitation [ 13 ].…”