Ejaculation

BackgroundThe 'omics' approach for a noninvasive diagnosis of male reproductive system disorders has gained momentum during the last decade, particularly from a screening and prognosis point of view. Due to the rapid development in assisted reproductive technologies (ART) over the years, the major focus of proteomic studies has been around the ejaculated spermatozoa. Although seminal plasma is not a requirement for ART, the question arose whether the role of seminal plasma is merely to transport spermatozoa.Main bodySeminal plasma (SP) contains a large diversity of proteins that are essential not only for sperm transport, but also for sperm protection and maturation. Most of the proteins bind to sperm surface through exosomes (epididymosomes and prostasomes), modulating sperm function, interaction with the female reproductive tract and finally fertilization. This review focuses on the state-of-art discoveries regarding SP proteome and its role in fertilization.ConclusionTissue-specific proteins in the SP have emerged as fundamental contributors for protein biomarker discovery. This is important for a noninvasive diagnosis of male infertility and development of new therapeutic approaches. Moreover, ART success rates may be improved by taking into account the critical role of seminal proteome in fertilization.

BackgroundSeveral factors have been shown to influence semen parameters, one of which is sexual abstinence; a clinical criteria included in the semen evaluation to provide maximum sperm quality. The aim of the present study was to assess the effect of a daily ejaculation frequency on conventional and functional semen parameters.MethodsSemen samples were collected daily over a period of two weeks of which every second sample per person was processed and analyzed according to the World Health Organization guidelines. Furthermore, mitochondrial function, intracellular reactive oxygen species production and sperm DNA fragmentation were evaluated by flow cytometry.ResultsTotal sperm count and seminal volume per ejaculation declined and remained decreased for the duration of the daily ejaculation period. However, conventional parameters such as sperm concentration, motility, progressive motility, morphology, vitality and functional parameters such as sperm plasma membrane integrity, mitochondrial membrane potential and DNA fragmentation was not significantly affected and remained similar to the initial measurement throughout the daily ejaculation period. Despite intra- and inter individual variations, the average values of the basic semen parameters remained above the WHO (2010) reference values throughout the daily ejaculation period. Interestingly, a decreasing trend in intracellular ROS production was observed, although statistically not significant.ConclusionsThe study shows that an extended 2 week period of daily ejaculation does not have major clinical effects on conventional and functional seminal parameters.

The purpose of this study was to evaluate fertility after different types of post-chemotherapy retroperitoneal lymph node dissection (RPLND). During 1980-1994, 192 patients with metastatic testicular cancer underwent post-chemotherapy RPLND with a gradual shift from modified bilateral template RPLND to nerve-sparing RPLND. Modified bilateral template RPLND was done in 92% of the patients operated during 1980-1984 as compared to 16% during 1989-1994. Pre- and post-treatment fertility was assessed by microscopic sperm analysis, determination of serum FSH and information on ejaculation and paternity. There was no significant difference of the survival rates between the three treatment periods. Antegrade ejaculation was preserved in 11% of the patients after modified bilateral template RPLND as compared to 89% after the nerve-sparing operation technique. The median ejaculatory volume decreased post-operatively, serum FSH increased and sperm density remained unchanged. Fifty-six patients attempted fatherhood after their treatment, and 27 fathered at least one child after an observation-time of 55 months, nine of them by assisted fertilization. Patients with initially advanced testicular cancer but limited residual retroperitoneal masses after induction chemotherapy can safely undergo limited post-chemotherapy RPLND as a part of multimodality treatment. After nerve-sparing RPLND antegrade ejaculation is preserved in 89% of the patients though the ejaculatory volume decreases after RPLND. Post-treatment fatherhood can be achieved in at least 50% of the patients attempting paternity.

When males compete, sexual selection favors reproductive traits that increase their mating or fertilization success (pre- and postcopulatory sexual selection). It is assumed that males face a trade-off between these 2 types of sexual traits because they both draw from the same pool of resources. Consequently, allocation into mate acquisition or ejaculation should create similar trade-offs with other key life history traits. Tests of these assumptions are exceedingly rare. Males only ejaculate after they mate, and the costs of ejaculation are therefore highly confounded with those of mating effort. Consequently, little is known about how each component of reproductive allocation affects a male's future performance. Here, we ran an experiment using a novel technique to distinguish the life history costs of mating effort and ejaculation for mosquitofish (Gambusia holbrooki). We compared manipulated males (mate without ejaculation), control males (mate and ejaculate), and naïve males (neither mate nor ejaculate) continuously housed with a female and 2 rival males. We assessed their growth, somatic maintenance, mating and fighting behavior, and sperm traits after 8 and 16 weeks. Past mating effort significantly lowered a male's future mating effort and growth, but not his sperm production, while past sperm release significantly lowered a male's future ejaculate quantity, but not his mating effort. Immune response was the only trait impacted by both past mating effort and past ejaculation. These findings challenge the assumption that male reproductive allocation draws from a common pool of resources to generate similar life history costs later in life. Instead, we provide clear evidence that allocation into traits under pre- and postcopulatory sexual selection have different trait-specific effects on subsequent male reproductive performance.