Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.

The origin of immunoglobulins in semen.

Abstract: IgG and IgA, albumin and lactoferrin as well as the semen compartment parameters acid phosphatase, fructose and spermatozoa were determined in separately collected fractions of the same ejaculate of some normal donors. The distribution over the fractions per ejaculate of IgG, IgA and albumin was generally more or less similar to the distribution of acid phosphatase indicating that the bulk of these proteins enters the semen via the prostate and not via the vesicles or testis and epididymis. The distribution of lactoferrin unexpectedly was not clearly related to fructose. IgM could not be detected. The concentrations in the (eight) total ejaculates expressed as percentages of the serum concentrations were for albumin slightly higher than for IgG, both in the order of 1% and moreover correlated with each other, indicating that IgG reached the seminal fluid in general by transudation from the circulation. The relative IgA concentrations could not be measured exactly but seemed to be slightly higher than of albumin, and not correlated to albumin concentrations, suggesting that local production of IgA may occur also.

Melatonin protects ram spermatozoa from cryopreservation injuries in a dose-dependent manner

Abstract: Cryopreservation harms spermatozoa at different levels and thus impairs their fertilizing ability. The role of melatonin in protecting spermatozoa from different kind injuries has been widely reported. Thus, this study tested whether the addition of melatonin to ram semen freezing extender could exert a protective effect and ameliorate postthawing sperm function. Melatonin was added to recommended ram extender to yield five different final concentrations: 0.001, 0.01, 0.1, 1, and 10 mm. A control group without melatonin supplementation was included. Spermatozoa viability, motility parameters, and intracellular ATP concentrations were evaluated both before and after cryopreservation, while DNA integrity and in vitro fertilizing ability were evaluated only after thawing. Obtained results showed that the concentration of 1 mm melatonin led to higher viability rates, higher percentages of total motile and progressive motile spermatozoa, higher percentages of spermatozoa with average rapid and medium velocity, higher intracellular ATP concentrations, and higher DNA integrity among semen frozen in control and melatonin-supplemented extenders (P<0.05). In addition, results obtained after the IVF test showed that at 1 mm concentration, melatonin led to a faster first embryonic division and to higher total cleavage rates compared to the other experimental groups (P<0.05). No difference in embryo output was observed among the six experimental groups. In conclusion, the addition of melatonin to ram semen freezing extender protected spermatozoa during cryopreservation in a dose-dependent manner. These results are likely to be mediated by its well-known antioxidant properties, even if a direct action of the indolamine cannot be ruled out.

Equine seminal plasma reduces sperm binding to polymorphonuclear neutrophils (PMNs) and improves the fertility of fresh semen inseminated into inflamed uteri.

Abstract: Seminal plasma (SP) is known to have immunosuppressive properties in several species. Equine SP has been reported to reduce or inhibit chemotaxis, phagocytosis and complement activity in vitro. The type and amount of the SP component that suppresses sperm-polymorphonuclear neutrophil (PMN) binding in vitro was determined, and the effect of such suppression on the fertility of mares inseminated in the presence of uterine inflammation, was analyzed. Sperm cells were suspended in either SP, semen extender or a mixture of both, and each was mixed with PMN-rich uterine secretions collected at 12 h after artificial insemination (AI). SP reduced binding between spermatozoa and PMNs significantly (P < 0.05). Fertile spermatozoa were suspended in SP or semen extender and used to inseminate mares 12 h after the induction of uterine inflammation. The pregnancy rate was normal (77%) when spermatozoa were suspended in SP, but was dramatically reduced to only 5% when spermatozoa were suspended in extender. The proteins from SP, blood plasma (BP) and a skim-milk-based semen extender (skim milk extender, SME) were precipitated by ammonium sulfate, resuspended in PBS and dialyzed. The effect of the precipitated proteins on sperm-PMN binding was compared with fresh, untreated SP. Both fresh SP, and isolated SP proteins reduced sperm-PMN binding (P < 0.001). Conversely, proteins isolated from either BP or SME did not reduce sperm-PMN binding. The different concentrations of SP proteins used showed a dose-dependent suppression of sperm-PMN binding. Concentrations of 1 mg/ml SP protein significantly reduced sperm-PMN binding and 6 mg/ml reduced the binding to a level similar to that observed with fresh whole SP (P < 0.001). Finally, SP protein digested with proteinase K resulted in the complete loss of SP suppressive activity confirming that the effective component is a proteinaceous substance.