Immunomodulatory cytokines in human seminal plasma correlate with immunomodulatory steroids

7alpha-Hydroxy-dehydroepiandrosterone and its 7beta-hydroxyepimer, which act as local immunomodulatory agents, dehydroepiandrosterone, cortisol, and major androgens, together with four cytokines-interleukins 2, 4, 10, and IFN-gamma, reflecting the activity of TH1 or TH2 cells present in semen, were measured in seminal plasma from 35 male donors. Cortisol, dehydroepiandrosterone, its sulfate, 7-hydroxy-dehydroepiandrosterone epimers, testosterone, and estradiol were also measured in their blood serum. Steroids and interleukins in semen as well as serum steroids and seminal interleukins were mutually correlated to find out whether a relationship between immunomodulatory steroids and cytokines influencing the immune environment does exist. A highly significant (P<0.001) positive correlation was found between seminal 7beta-hydroxy-dehydroepiandrosterone and IFN-gamma, while a negative correlation was found between cortisol and IL-10. Highly significant positive correlations were also found between serum 7alpha-hydroxy-dehydroepiandrosterone and seminal IFN-gamma and between serum 7beta-hydroxy-dehydroepiandrosterone and seminal IL-2, while a negative correlation was found between serum dehydroepiandrosterone and seminal IL-10. Different and in some instances, even contradictory findings concerning the influence of dehydroepiandrosterone and cortisol on TH1 and TH2 cytokines were observed in seminal plasma as compared to those found by others in serum. The differences can be ascribed to the different environments of mucosal and systemic immunity. Correlations between the levels of steroids and cytokines in seminal plasma did not always correspond to the correlations between given cytokines and hormones in sera. The results, however, are in agreement with our recent finding of an autonomous production of these steroids in the male reproductive tract.     

Biomarkers of in vivo fertility in sperm and seminal plasma of fertile stallions

The global proteome of sperm and seminal plasma of fertile stallions was investigated to determine whether associations with relative in vivo fertility exist. Seven stallions at stud in a commercial breeding station were collected throughout the breeding season and bred to a total of 164 mares to determine conception rates. On three occasions during the breeding season, raw semen was obtained from a regular collection for proteomic analysis using two-dimensional electrophoresis and also assessed for routine semen quality end points. First cycle conception rate was negatively related to ejaculate volume (r = −0.43, P = 0.05) and total IGF1 content (ng) per ejaculate (r = −0.58, P = 0.006), whereas overall pregnancy rate was positively related to sperm concentration (r = 0.56, P = 0.01). The abundance of three proteins known to be involved in carbohydrate metabolism in sperm was positively related to fertility. Furthermore, the abundance of four seminal plasma proteins were identified as being negatively related to fertility; these were identified as kallikrein-1E2 (KLK2), clusterin, and seminal plasma proteins 1 (SP1) and 2 (SP2). Abundance of cysteine-rich secretory protein 3 (CRISP3) was positively related to first cycle conception rate (r = 0.495, P = 0.027) and may provide a good marker of fertility. Based on stepwise regression analysis, clusterin and SP1 in seminal plasma together with sperm citrate synthase were predictive of fertility (r = 0.77, P < 0.0001). This study identified proteins within sperm and seminal plasma that could serve as biomarkers of semen quality and fertility in stallions.     

Determination of zinc fractions in human blood and seminal plasma by ultrafiltration and atomic absorption spectrophotometry

A simple and reliable method is described which combines ultrafiltration technique with atomic absorption spectrophotometry to determine the Zn fractions in human blood plasma and seminal plasma. Ultrafiltrable, loosely bound, and firmly bound Zn can be measured using this method in the presence or absence of ethylene-diaminetetraacetic acid (EDTA). The YMT membranes for the ultrafiltration must be rinsed thoroughly before use. In contrast to Zn in blood plasma, a large part of Zn in the seminal plasma was found to be ultrafiltrabe. This method can be applied to study the physiologically active part of Zn in body fluids related to various disease states.     

Effect of seminal plasma on the characteristics and fertility of rabbit spermatozoa

The effects of different dilutions of seminal plasma (SP) on the qualitative characteristics of rabbit spermatozoa and on their fertilising ability were analysed. Ejaculated semen was centrifuged twice and the sperm resuspended in media with decreasing ratios of SP/Tris: (1/2; 1/5; 1/10; 1/20; 1/30; 1/100) until the complete substitution was with SP. The control constituted sperm in undiluted SP. Samples were maintained at 37 degrees C and kinetic analysis done at fixed intervals (0-6h). Also the thiobarbituric reactive substances (TBA-RS) values were determined. Rabbit sperm suspended in Tris, or with extremely low content of SP, lost motility and viability within 1-3h, while sperm suspended in SP either undiluted or diluted up to 10-fold, showed similar motility during the 6h period (from 39 to 49%). Further dilutions of SP (1/20-1/30) had no effect during the initial 2h of storage but thereafter the decline of motility was more marked (after 6h: from 0 to 17%). Kinetic parameters followed the same trend and differences were particularly marked after storage: the highest values were in samples diluted up to 1/10; a sharp decline in motility characteristics was observed at higher dilutions. The addition of SP (1/2 v/v) to immotile sperm reactivated 35.5% of cells. However, SP did not significantly affect fertility rate or litter size possible involving an interaction with the female reproductive tract. SP reduced lipid oxidation (TBA-RS) of semen only after storage. A positive correlation between final TBA-RS and cell viability indicated that peroxidation was one of the cause of rabbit sperm deterioration during conservation.     

Cholesterol-to-phospholipid ratio in whole sperm and seminal plasma from fertile stallions and stallions with unexplained subfertility

Semen samples were collected from six fertile stallions and seven stallions with unexplained infertility. Percentages of motile sperm (77.5 +/- 11.3 versus 67.5 +/- 12.2, P = 0.2), and progressively motile sperm (70.8 +/- 13.6 versus 60.7 +/- 14.0, P = 0.2) were similar between fertile and subfertile stallions, respectively. Morphologic characteristics in ejaculates of control and affected stallions (% normal: 60.2 +/- 18.2 versus 52.9 +/- 11.3, P = 0.4; % abnormal heads 7.3 +/- 4.8 versus 12.1 +/- 5.0, P = 0.11; and % abnormal acrosomes 1.6 +/- 2.1 versus 3.0 +/- 3.4, P = 0.4) did not differ. After incubation with the calcium ionophore A23187, acrosome reaction rate of sperm from fertile stallions was 96 +/- 2.8% whereas only 2.9 +/- 2.5% of sperm from stallions with unexplained subfertility had acrosome reacted (P < 0.001). Molar amounts of cholesterol and phospholipid in whole sperm and seminal plasma did not differ (P > 0.1) between fertile and subfertile stallions. However, the molar ratio of cholesterol-to-phospholipid was 2.5 times greater in the seminal plasma (P = 0.09) and 1.9 times greater (P = 0.009) in whole sperm of subfertile stallions compared to fertile stallions.     

Isolation and purification of an organ-specific autoantigen from rabbit seminal plasma

A specific autoantigen of rabbit accessory glands was isolated and purified from seminal plasma using DEAE-Sephadex batch adsorption and Sephadex G-100 chromatographic fractionations. The autoantigen appeared homogeneous by polyacrylamide electrophoresis and by immunodiffusion. It has an extinction coefficient at 284 mμ (E_1cm^1%) of 6.42. It contains 87.73% of polypeptides. The carbohydrate moiety is composed of 9.21% hexose, 1.03% hexosamines, 0.33% fucose. From these chemical values the autoantigen has been identified as glycoprotein.     

A rapid method for the determination of glycerophosphorylcholine in rabbit and bull seminal plasma

Glycerophosphorylcholine is the only phosphate-containing compound of bull or rabbit seminal plasma that is eluted by water from a semimicro column of Dowex 1-acetate. This observation has permitted development of a rapid method for glycerophosphorylcholine analysis.     

Immunosuppression by seminal plasma from fertile and infertile men: Inhibition of natural killer cell function correlates with seminal PG concentration

Human seminal plasma has uniquely high concentrations of PGE and 19-hydroxy PGE but the function of these PGs has not been elucidated. PGs of the E series have been shown to be paracrine and autocrine regulators of the function of immune cells and high levels of PGE have been shown consistently to suppress function in such cells. Human seminal plasma has a potent immunosuppressive effect and evidence is accumulating that this is largely due to PG components. In this study the effects of human seminal plasma on the killing activity of natural killer (NK) cells as judged by 51Cr release from K562 cells have been studied in groups of fertile and infertile men. Although there was no significant difference in the PGE, 19-hydroxy PGE or the NK cell inhibitory activity in the two groups, the inhibition of NK cell activity was closely correlated with the PGE and the 19-OH PGE content of the seminal plasma in the fertile group. This finding is further evidence that the major contribution to the immunosuppressive properties of human semen is provide by the high concentration of PGs of the E series in this fluid.     

Calcium-binding protein in bull seminal vesicle secretion and seminal plasma.

A protein which showed high affinity for calcium ions was isolated from bull seminal vesicle secretion and seminal plasma. Its calcium-binding activity depended on the ionic strength and pH of the medium. The dissociation constant was 7-7 X 10(-7) M and there were 14 binding sites per protein molecule. The molecular weight of calcium-binding protein from bull seminal vesicle secretion, estimated by the gel filtration method, was 110,000. The protein may be involved in the regulation of the calcium ion level in seminal plasma.     

A radioimmunoassay of plasma unconjugated and conjugated estetrol.

A radioimmunoassay for the measurement of both unconjugated and conjugaged estetrol in plasma has been developed. The antiserum obtained after 6 months of immunization with 6-oxoestetrol-6-(O-carboxy-methyl)oxim-BSA was used at a final dilution of 1:90,000 and showed almost no cross reaction with other steroids except for estriol at 1.24%. Esterol-glucosiduronate was synthesized by incubating with adrenalectomized rat liver homogenate and uridine diphosphoglucuronic acid. Then, plasma estetrol-glucosiduronate was measured in the same manner for unconjugated estetrol after hydrolysis with beta-glucuronidase. Sephadex LH-20 column chromatography (7X110 mm, benzene:methanol, 85:15) was employed for accurate assessment. The sensitivity was 10 pg and the smallest amount measurable was 40 pg/sample. The method bland was consistently negligible. The intra and inter assay precision was 11.8% and 14.2% for unconjugated estetrol and that for estetrol-glucosiduronate was 13.5% and 17.1%.