The objective of this study was to investigate the effects of different levels of seminal plasma (SP) on boar sperm quality, antioxidant capacity and bacterial concentrations during liquid storage at 17°C. Boar sperm was diluted with Beltsville Thawing Solution (BTS) consisting of 0, 25, 50 and 75% (v/v) of SP. Total motility, progressive motility and dynamic parameters were assessed by the computer assisted sperm analysis (CASA) system. Acrosome and plasma membrane integrity were measured by FITC-PNA/DAPI and SYBR-14/PI staining, respectively. In addition, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, and reactive oxygen species (ROS) levels were detected using commercial assay kits. Bacterial concentrations were assessed by turbidimetric assay. Our results showed that 25% SP markedly improved total motility, progressive motility, sperm dynamic parameters, acrosome integrity compared with 0, 50 and 75% SP (P < 0.05). In addition, 25% SP significantly increased T-AOC but decreased MDA content and ROS levels compared with 0, and 75% SP (P < 0.05). Moreover, 25% SP significantly decreased the bacterial concentrations in extended semen compared with 50% and 75% SP, however, which was higher than with 0% SP (P < 0.05). These results suggest that 25% SP can promote boar sperm quality through enhancing its antioxidant capacity during liquid storage.

The oviduct is a dynamic organ in which final gamete maturation, fertilization and early embryo development take place. It is considered to be a sterile site; however the mechanism for sterility maintenance is still unknown. S100A7 is an anti-microbial peptide that has been reported in human reproductive tissues such as prostate, testicle, ovary, normal cervical epithelium and sperm. The current work reports the presence of S100A7 in the Fallopian tube and its localization at the apical surface of epithelial cells. For comparison, porcine S100A7 was used for antibody development and search for peptide in reproductive tissues. Although present in boar seminal vesicles and seminal plasma, S100A7 was not detected on female porcine organs. Also, in contrast with the human protein, porcine S100A7 did not show anti-microbial activity under the conditions tested. Phylogenetic analyses showed high divergence of porcine S100A7 from human, primate, bovine, ovine and equine sequences, being the murine sequence at a most distant branch. The differences in sequence homology, Escherichia coli-cidal activity, detectable presence and localization of S100A7 from human and pig, suggest that there are possible different functions in each organism.

This study was done to evaluate the effects of two sublethal doses of gossypol (4 and 20 mg/kg of BW, every other day) on some amino and fatty acid concentrations in male rabbit seminal plasma. Rabbits were chosen as an experimental animal owing to the fact that they are excellent model for reproductive toxicological effects. The experiment lasted 16 weeks and included two periods: a treatment period (first 8 weeks) where the animals were given the tested product, and a recovery period (second 8 weeks) where all drugs were withdrawn. Results showed that total amino acids (TAA), total essential amino acids (EAA), total non-essential amino acids (non-EAA) and EAA/non-EAA ratio were decreased in a dose-dependent manner during gossypol treatment. The deleterious effect on TAA concentrations was mainly due to the reduction in total EAA. However, these concentrations regained their normal values after gossypol cessation. Basic, acidic, neutral amino acids and basic/acidic amino acids ratio decreased in a dose-dependent manner by gossypol treatment. Additionally, gossypol administration caused decreases in total unsaturated fatty acids (USFA) and increases in total saturated fatty acids (SFA) and the SFA/USFA ratio in a dose-dependent manner. During the recovery period, total SFA and USFA showed significant reduction and significant increase, respectively, after gossypol withdrawal. In conclusion, gossypol administration affected rabbit seminal plasma concentrations of amino and fatty acids in a dose-dependant manner. Gossypol reduced TAA, total EAA and total non-EAA. Additionally, gossypol caused decreases in total USFA and increases in total SFA. These deleterious effects were associated with poor-quality semen observed in our previous studies.

The effects of osmolality and accidental urine contamination on spermatozoa velocity and motility were studied, combined with an examination of the biological characteristics of stripped and testicular sperm. Analysis of Northern pike sperm showed higher ionic concentrations of Na+ (123 ± 9 mM), Cl- (127 ± 7 mM), and K+ (35 ± 5 mM) in the seminal fluid of testicular sperm (TS), than in that of stripped sperm (SS): Na+ (116 ± 9 mM), Cl− (116 ± 7 mM) and K+ (25 ± 4 mM). Highest osmolality of seminal fluid was observed in TS with a value of 358 ± 77 mOsmol kg−1 compared with 273 ± 21 mOsmol kg−1 for SS and 68 ± 36 mOsmol kg−1 for urine. A significantly higher spermatozoa concentration was observed in TS (34 ± 5 × 109 ml−1) than in SS (23 ± 4 × 109 ml−1). Spermatozoa concentration per male and per kg body weight was 22 ± 17 × 109 for TS and 18 ± 2 × 109 for SS, respectively. Both TS and SS showed significantly higher spermatozoa velocities and motilities after dilution in urine than after dillusion in distilled water during the activity period. In conclusion, the results obtained from the present study provide information on northern pike sperm physiology that be used to improve sperm management efficiency for this species.

Eighteen spermiating males were randomly selected from a hatchery-reared stock and electronically tagged to record changes in their sperm quality parameters (spermatozoa morphology, ultrastructure and motility, ionic composition and osmolality of the seminal plasma, and sperm volume and density) during the spawning season. Stripping was performed at the beginning of March, April and May. The Barbus barbus spermatozoon has a head without acrosome, a midpiece with 4–6 mitochondria and proximal and distal centrioles, and a flagellum with the typical 9+2 pairs of microtubules. Apart from posterior width of the midpiece, morphological and ultrastructural parameters changed significantly during the reproductive season; generally by decreasing toward the end of reproductive season. Sperm volume also decreased from 0.42 in March to 0.15 ml in May, and density from 18.81 in March to 12.45 × 109 spz ml−1 in May. Osmolality (mOsmol kg−1) was 268 ± 4, 276 ± 2 and 268 ± 2 in March, April and May respectively. Chloride, sodium, calcium and potassium ion concentrations (mM) did not show significant differences between March and April (Cl−: 125.3 vs. 120.5, Na+: 75.7 vs. 69.7, Ca2+: 0.4 vs. 0.3 and K+: 84.7 vs. 84.0). The percentage of motile spermatozoa at 15 s post activation did not show a significant difference between dates, but the highest spermatozoa velocity at 15 s post activation was observed in April (91.4 ± 3.2 µm s−1) and then decreased significantly towards the end of the reproductive season (80.6 µm s−1 in May). However, lowest spermatozoa velocity was measured in March (70.4 ± 1.9 µm s−1). This study supports the hypothesis that longer spermatozoa swim faster. Within one stripping, velocity and percentage motility decreased significantly with time post activation. In conclusion, changes observed in B. barbus sperm parameters during the reproductive season, suggest there is association between such changes and spermatozoa aging processes.

The seminal plasma PSP-I/PSP-II spermadhesin is able to preserve, in vitro, the viability of highly extended boar spermatozoa, suggesting it might be used as a suitable ameliorator for the damaging effects of sperm handling, including in vitro fertilization. However, little is known about the ligand capability of PSP-I/PSP-II as regards the zona pellucida (ZP) or its possible role in gamete interaction. The present study evaluated the effect of the presence of PSP-I/PSP-II (1.5 mg/ml) during in vitro oocyte maturation and also during co-incubation of frozen-thawed boar spermatozoa with either immature (IM) or in vitro matured (IVM) oocytes, either enclosed by cumulus cells or denuded. Exposure of the gametes to the heterodimer during in vitro gamete co-incubation showed a significant blocking effect of sperm penetration rates and a decreased number of spermatozoa per oocyte in both IM and IVM denuded oocytes. Such an effect was not present in cumulus-enclosed oocytes, suggesting the effect could be mediated by exposed ZP receptors. In addition, when PSP-I/PSP-II was added to the IVM medium, oocyte maturation rates were significantly reduced. In conclusion, the results suggest that PSP-I/PSP-II, when present in vitro, blocks sperm–ZP binding.

Proteases and protease inhibitors were detected in the seminal plasma, blood plasma, skin mucus and spermatozoa. Their molecular weights were estimated using SDS-PAGE under non-reducing conditions. The results demonstrate that the two main bands of anti-proteinase activity (APA) detected earlier in common carp seminal plasma with molecular weight of approximately 47 and 58 kDa are also present in other fluids. The intensity of staining was highest in blood and seminal plasma. The intensity in skin mucus was visible, but in a sperm extract it was faint. An additional fast migrating band (30 kDa) was observed only in seminal plasma. Highest APA was found in blood and seminal plasma followed by skin mucus. The activity in sperm extracts was low. The two serine-like proteases with molecular weight of 79 and 189 kDa in seminal and blood plasma have also been found. In skin mucus, protease of 79 kDa was also present. Metalloproteinases with molecular weights of 61 and 69 kDa were found in seminal and blood plasma but metalloproteinases of 44 and 38 kDa were observed only in seminal plasma. Although metalloproteinases, of molecular weight ranging between 61 and 75 kDa, were also visible in a sperm extract, the experimental approach used in this study did not allow unequivocal identification of unique proteases of spermatozoa. Blood plasma contains a serine protease and protease inhibitor not present in seminal plasma. Skin mucus also showed the profile of three unique proteases (two EDTA stimulated and one metalloproteinase). These results indicate that the analysis of proteases and their inhibitors makes it possible to distinguish contamination of milt with either blood or skin mucus. The physiological role of the detected protease-inhibitory system in fish seminal plasma is still unknown. It is possible that the protease inhibitor and proteases, unique for seminal plasma, are involved in a specific function of milt or testis (e.g. the control of spermatogenesis).

Anti-proteinase activity was demonstrated in the seminal plasma of cyprinid fish species (bream, chub, ide, dace, asp, goldfish, roach, common carp) using electrophoretic techniques combined with a detection method based on inhibition of bovine trypsin. We found species-specific protease inhibitors in the seminal plasma of cyprinids. At least three bands of protease inhibitors with different migration rates could be identified by native PAGE. Higher variability was characterized for bands with slower migration rates. Visualization of inhibitors after SDS-PAGE under non-reducing conditions allowed estimation of their molecular weights. Apparent molecular weights were within the range of 51–59 and 47–54 kDa for the bands with slower and moderate migration rates, respectively. The molecular weight of fast migration bands for roach and common carp were estimated to 23 and 30 kDa, respectively. Inhibitors of common carp seminal plasma differed in their affinity toward serine proteases. Three inhibitors in common carp seminal plasma could be visualized using cod and bovine trypsin, but only two inhibitors (of high molecular weight) were recognized with chymotrypsin. There were differences in anti-proteinase activity and seminal plasma protein concentration in relation to the origin of common carp seminal plasma (breeding lines) and time of milt collection (spawning vs. post-spawning season).

Fifteen sexually mature rams, five each of Barki, Awassi (I, imported from Syria) and Awassi (LB, locally born in Egypt) were used to study the biochemical and enzymatic properties of seminal plasma for 12 months. The biochemical analyses of ram seminal plasma indicated that the highest values of total protein, albumin (A), globulin (G), fructose, total lipids and cholesterol were recorded in late summer and early autumn, while A/G and AST/ALT ratios exhibited the lowest values. Lowest values of the same parameters were recorded in winter and late spring, while ratios of A/G and aspartate amino transferase (AST)/alanine amino transferase (ALT) showed the highest values in spring. AST enzyme activity showed highest activity in winter and summer and lowest activity in autumn, while ALT exhibited the highest activity in winter and the lowest activity in spring. The relationships between these parameters and semen quality are discussed.

Fertile female Wistar rats were immunised against rat and mouse seminal vesicle secretion (SVS) to test the production of allo-antibodies and the effect of the antibodies elicited on fertility. Twenty-six per cent of the rat and mouse SVS-immunised females were infertile after the treatment. The sera were titrated by ELISA and used in Western blots to detect the proteins recognised. Although neither the antibody titres nor the proteins recognised by the sera showed a close relation with the degree of fertility, in all females the highest antibody titre in the fluids from the genital tract was found in the oviductal fluid and during the night of oestrus. This fact suggested that the site of action of the antibody could be the oviduct. Similar results were obtained using mouse SVS as immunogen – a fact that can be related to the antigenic similarity between the SVS of the two species. The antibodies react with the spermatozoa but not with eggs or embryos. Analyses performed on embryos collected from sterile females showed that there was a delay in fertilisation and normal embryogenesis. Our results suggest that SVS proteins are antigenic and that these antigens are bound to the spermatozoa and could take part in early pre-fertilisation events such as capacitation or sperm transport.

Un lot de 40 mâles d'une souche de truite arc-en-ciel (Salmo gairdneri) à reproduction printanièrea été suivi. Seuls les spermes d'un volume supérieur ou égal à 6 ml ont été caractérisés et congelés enboulettes. L'analyse factorielle des correspondances entre les caractéristiques et la fécondance dusperme après 5 à 9 mois de congélation a montré en particulier que l'aptitude à la cryoconservationpeut être caractérisée par l'analyse du plasma séminal : les spermes médiocres sont associés à uneosmolarité plasmatique élevée (260 m-osmoles) et/ou une teneur élevée en protéine 42 KD, l'un desconstituants majeur de la membrane des spermatozoïdes; les très bons spermes sont associés àl'absence de protéine 42 KD dans le liquide séminal. Ces résultats renforcent l'idée que l'aptitude à lacryoconservation du sperme de truite dépend en premier lieu de la qualité de la membrane des spermatozoïdes.