Quantification of prostaglandins in human seminal fluid

Effect of seminal plasma on dendritic cell differentiation in vitro depends on the serum source in the culture medium

Dendritic cells (DCs) are key in shaping immune responses and are recruited to the human cervix after coitus by seminal plasma (SP). SP has been shown to skew the differentiation of monocyte-derived DCs towards an anti-inflammatory profile when cultured in medium containing fetal calf serum (FCS). Here, we confirmed that SP skewed DCs cultured in fetal bovine serum (FBS) towards a tolerogenic profile. To create a setting more similar to the in vivo situations in humans, we tested the immune regulatory effect of SP on DCs in cell cultures containing human serum (HS). SP-DCs cultured in HS did show increased CD14 and decreased CD1a, indicating an inhibited maturation phenotype. Gene expression of TGF-β and IL-10 and IL-10 protein expression were elevated in LPS-activated SP-DCs, whereas IL-12p70 protein levels were decreased compared to LPS-activated control DCs. In contrast to FBS culture conditions, in the presence of HS co-cultures of SP-DCs with allogeneic peripheral blood mononuclear cells (PBMCs) did not result in decreased T cell proliferation and inflammatory cytokine production. Thus, under HS culture conditions SP can skew the differentiation of monocyte-derived DCs phenotypically towards alternatively activated DCs, but this immune regulatory phenotype is functionally less pronounced compared to SP-treated DCs cultured in FBS containing medium. These findings highlight the importance of the source of the serum that is used in SP treated cell cultures in vitro.

Rapid and slow hydroxylators of seminal E prostaglandins among men in barren unions

E prostaglandins are formed in seminal vesicles and can be oxygenated by (omega-1)-hydroxylation catalysed by cytochrome P450 to 19(R)-hydroxy metabolites. The latter are not further metabolized. Prostaglandin E1 (PGE1), PGE2, 19-hydroxy-PGE1 and 19-hydroxy-PGE2 were measured in seminal fluid of 95 men, who attended the clinic for infertility. After extractive isolation, the E prostaglandins were converted to B prostaglandins by alkali treatment and analysed by high performance liquid chromatography on beta-cyclodextrin silica with 17-phenyl-PGE2 as an internal standard. The relative amount of 19-hydroxy E-prostaglandins varied between 26% and 97%. Most (86%) of the men were classified as rapid or normal hydroxylators with PGE/19-hydroxy PGE ratios below 0.75, while 14% were slow hydroxylators. The relative amount of 19-hydroxy E1 and 19-hydroxy E2 showed a 96% covariation, which supports that a common enzymatic mechanism is operating on both E1 and E2 prostaglandins and that this mechanism is the major determinant for formation of 19-hydroxy compounds. We conclude that the relative amounts of PGE1, PGE2, 19-hydroxy-PGE1 and 19-hydroxy-PGE2 in seminal fluid vary, possibly due to polymorphic expression of this enzymatic mechanism. Total output of 19-hydroxy-PGE compounds, but not the primary PGE compounds was correlated with the output of seminal fructose, supporting that the 19-hydroxy prostaglandins are the normal end products of the seminal vesicles. Low sperm concentration found among men with high output of E prostaglandins could here simply be explained by dilution of spermatozoa by a high output of seminal vesicular fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of 19 (R)-OH prostaglandin E2 as a selective prostanoid EP2-receptor agonist

The physiological significance of the formation of large quantities of 19(R)-hydroxy prostaglandin E's (19-OH PGE) from PGE1 and PGE2 in human seminal plasma is intriguing. The concept that prostaglandins exert their biological effects by interacting with specific receptors, according to the current working classification for prostanoid receptors, was employed as a conceptual framework to re-examine the activity of 19(R)-OH PG's. In contrast to PGE2, which may indiscriminately stimulate a variety of prostanoid receptor subtypes, 19(R)-OH PGE2 exhibited selectivity for the EP2-receptor subtype. In EP1 (guinea pig ileum contraction), EP2 (cat trachea relaxation), and EP3 (chick ileum contraction) preparations where PGE2 is equipotent, 19(R)-OH PGE2 exhibited greater potency in the EP2-receptor population. Moreover, unlike PGE2, 19(R)-OH PGE2 did not stimulate an FP-receptor preparation (cat iris). 19(R)-OH PGE2 was devoid of activity at thromboxane A2-(TP), prostaglandin D2-(DP) and prostacyclin-(IP) sensitive receptors as indicated by its inability to cause human platelet aggregation or inhibit ADP-induced platelet aggregation. 19(R)-OH PGE1 had an entirely converse profile of activity. As a myotropic agent in the guinea pig and chick ileal preparations, 19(R)-OH PGE1 was approximately 1.5 orders of magnitude more potent than 19(R)-OH PGE2 but it appeared devoid of EP2-receptor stimulant properties. 19(R)-OH PGF2 alpha possessed very little biological activity in a diverse variety of isolated tissue preparations, indicating that 19-hydroxylation represents a highly efficient inactivation step for PGF2 alpha. The implications of the formation of receptor selective PGE derivatives in human seminal fluid for human reproductive physiology remains to be established.

The fertility potential of male cystic fibrosis patients

Men suffering from cystic fibrosis (CF) are considered to be infertile because of azoospermia. In testicular biopsies from two patients with CF normal spermatogenesis was found despite the absence of sperm in the ejaculate. Fructose and prostaglandin were not detectable in the semen whereas the levels of acid phosphatase and zinc were within normal limits, indicating normal prostatic function and absence of seminal vesicles. These findings may improve the possibility for male patients with CF to father a child.

Prostaglandins in human semen during fish oil ingestion: evidence for in vivo cyclooxygenase inhibition and appearance of novel trienoic compounds

Marine oils may offer cardiovascular benefits, but inhibition of prostaglandin E and prostaglandin F synthesis by fish oil has been found in animal studies, and such effects could alter physiological responses in man to a clinically significant degree. Since greater amounts of E and F-type prostaglandins are made in human seminal vesicles than in the rest of the body combined, the influence of n-3 supplements upon semen prostaglandins was assessed in 10 subjects before and after one month of taking 50 ml menhaden oil daily. Prostaglandins E1, E2 and their 19-hydroxy derivatives were measured by HPLC-UV as PGB's, and prostaglandin E3, 19-OH PGE3, and analogous PGF's by gas chromatography/mass spectrometry. Fish oil ingestion reduced concentrations of one- and two series prostaglandins (mean reduction in PGE's = 37%, in PGF's = 20%, p less than 0.05), while more than doubling the low amounts of PGE3 and PGF3 alpha, and their previously undescribed 19-hydroxy derivatives. Semen phospholipids were enriched in eicosapentaenoic acid after dietary fish oil, but sperm counts and motility were not altered during the study. Since dietary fish oil reduces prostaglandin concentration in semen, clinical trials of n-3 fatty acids should also evaluate other possible results of in vivo cyclooxygenase inhibition.

Variation in, and inter-relationship between, prostaglandin levels and other semen parameters in normal men

In each of 135 ejaculates from 46 healthy men, semen volume, various sperm parameters and the level of prostaglandins (PGs) were determined. Data were analysed to determine the within- and between-subject variability, the effect of abstinence period and the correlation between different parameters. Data which did not reveal a Gaussian distribution were transformed logarithmically. For all variables the between-subject variance exceeded the variation within subjects (P less than 0.001). Variation in time of abstinence between 1 and 3 days influenced semen volume and sperm content as well as the content of 19-hydroxylated PGs, but did not affect sperm motility or the concentration of PGE or PGF. A significant negative correlation was found between the seminal content of PGE and PGF and the total sperm count as well as the sperm concentration. Sperm motility was related to the balance between the content of 19-hydroxy PGE and 19-hydroxy PGF but not to their separate concentrations. The ratio between 19-hydroxy PGE and 19-hydroxy PGF did not change when the time of abstinence differed. Synthesis of the two 19-hydroxylated PGs seemed to be regulated by the same mechanism, but their hydroxylation capacity still varied considerably between individuals.

The effects of oral administration of prostaglandin E2 on the human ejaculate

A single 1 mg dose of prostaglandin (PG) E2 was given orally to 19 men. Ejaculates were obtained 90 minutes and 24 and 48 hours thereafter. Before treatment, each man delivered another three semen samples with the same time intervals as during the study period. PGE2 was also administered to seven men during naproxen treatment and ejaculates were sampled as above. PGE2 did not influence the 90 minutes' posttreatment ejaculates, but after 24 hours there was a significant (P less than 0.05) decrease in sperm counts as compared to the control samples. The change in sperm count was suggested to be due to an effect of PG on the contractile elements in the deferent duct. Sperm motility, viability, and morphology as well as semen volume and adenosine triphosphate (ATP) content remained unchanged. The total semen PGE content was increased 24 hours after treatment from 169 micrograms/ejaculate to 213 micrograms/ejaculate (P = 0.02). In the combined PGE2/naproxen treatment the PGE levels were significantly (P less than 0.05) elevated in the ejaculate 48 hours after treatment. The increase may indicate an increased de novo synthesis of prostaglandins. Based on the results from the analysis of the composition of the 19-hydroxy PGF-isomers with and without naproxen treatment, it is speculated that oral PGE2 influences the cyclo-oxygenase activity.

Endocrine, seminal and peripheral effects of depot medroxyprogesterone acetate and testosterone enanthate in men

Depot medroxyprogesterone acetate (D-MPA, 250 mg) and testosterone enanthate (TE, 200 mg) were administered twice with a 4-week interval to nine healthy men, and the levels in blood of steroids, gonadotrophins, lipoproteins, sex hormone binding globulin (SHBG) and prostaglandins (PGs) were measured, as well as steroid levels in semen and the sperm count and motility. The hormones analysed were: MPA, testosterone, androstenedione (A), dihydrotestosterone (DHT), oestradiol (E2), cortisol (C), luteinizing hormone (LH), follicle stimulating hormone (FSH) and the sulphoconjugated forms (-S) of testosterone, DHT, pregnenolone (5-P) and dehydroepiandrosterone (DHEA). Peak values of MPA (10.2 +/- 4.6 nmol/l) and testosterone (28.0 +/- 10.0) were found in the first blood samples 2 days after each injection. Thereafter the levels of MPA decreased gradually and reached the limit of detection 18-20 weeks after the second injection. Blood levels of testosterone fell sharply from the peak values and were grossly subnormal 2 weeks after each injection; levels did not return to pretreatment values during 24 weeks of follow-up. The pattern of change of DHT, A, E2 and sulphonated androgens was similar to that of testosterone. These data suggest that D-MPA and TE are absorbed at similar rates, and that the TE is metabolized rapidly. The subsequent reduction in the levels of A, testosterone-S and DHT-S was less marked and reached pretreatment values earlier than did the testosterone levels. No obvious changes were found in the levels of C, 5-P-S and DHEA-S or in the seminal plasma levels of the various steroids studied. The blood levels of LH and FSH fell precipitously 2 days after the first injection, then started to increase 4 weeks after the second injection to reach pretreatment values 12 weeks later. Of the lipoproteins studied only the levels of HDL-cholesterol and SHBG were found suppressed after treatment. Severe oligozoospermia and the complete absence of progressively motile sperm, in at least one semen sample, was observed in all subjects at 3-7 and at 5-16 weeks, respectively, after the last injection, suggesting that the men were infertile for at least 1 month after treatment. A spurious increase in the PG content of semen was also observed. In spite of the low blood testosterone levels, no subject reported changes in sexual behaviour or other signs of anabolic imbalance during or after the study. However, the increase in levels of E2 in some individuals should be kept in mind as a possible cause of side-effects.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of prostaglandins on human sperm function in vitro and seminal adenosine triphosphate content

The aim of the present study was to evaluate the effect of addition of physiologic amounts of different prostaglandins normally present in semen, on sperm motility, on sperm penetration capacity in cervical mucus in vitro, and on the adenosine triphosphate (ATP) concentration in semen. Semen samples were obtained from volunteers who were attending the fertility outpatient clinic. Sperm motility was measured on a video recorder with a built-in timer, sperm penetration by the Kremer test, and ATP by bioluminescence assay. The addition of 19-hydroxy prostaglandin (PG) E to ejaculates positively stimulated sperm motility and sperm penetration capacity. The opposite effect was observed with 19-hydroxy PGF. PGE1, PGE2, and PGF2 alpha had no effect on either parameter, while PGF1 alpha reduced the sperm motility. The addition of 19-hydroxy PGE to ejaculates increased and the addition of 19-hydroxy PGF reduced semen concentrations of ATP. However, only the last-mentioned effect was statistically significant (P less than 0.05). It is suggested that, in particular, 19-hydroxy PGE and 19-hydroxy PGF are important regulators of sperm motility and that the effect may be mediated via effects on the ATP content in the spermatozoa.

Prostaglandin levels in infertile patients affected by asthenozoospermia and prostatitis

19-hydroxy-prostaglandins and prostaglandins of the E series (19-OH PGEs) were estimated in the seminal plasma of asthenozoospermic patients (n = 15) and individuals affected by prostatitis (n = 10) and compared to controls (n = 13) and secretory azoospermic patients (n = 8). All of them were free from infections (except individuals affected by prostatitis), biochemical and ultrastructural problems. The results indicate that endogenous prostaglandin levels (19-OH PGEs and PGEs) bear no correlation either to motility or absence of spermatozoa. Significant increases of PGEs were observed in patients affected with prostatitis. Surprisingly PGE levels showed no correlation with the levels of 19-OH PGEs.

Changes in corpus luteum content of prostaglandin F2 alpha and E in the adult pseudopregnant rat

Conflicting reports exist regarding the source of luteolytic PGF2 alpha in the rat ovary. To assess the quantities of different PGs, measurements of PGF2 alpha, PGE and PGB were performed by radioimmunoassay in the adult pseudopregnant rat ovary throughout the luteal lifespan. Ovaries of 84 rats were separated by dissection into two compartments, corpora lutea of pseudopregnancy and remainder of ovary. Tissue samples were homogenized and prostaglandins extracted and determined by radioimmunoassay. During the mid-luteal and late-luteal phases, levels of PGs were significantly higher in the corpora lutea of pseudopregnancy than in the remainder of ovary. An increase of PGF2 alpha-content in the corpus luteum was registered with peak-levels of 53.9 +/- 8.5 (mean +/- SEM, N = 18) ng/g tissue wet weight at day 13 of pseudopregnancy. PGE-levels reached peak-values at day 11 of pseudopregnancy (271.6 +/- 28.4 ng/g w w, mean +/- SEM, N = 12). PGB-levels were below detection limits in all compartments for all ages studied. The present study demonstrates increased availability of PGF2 alpha in the corpus luteum during the luteolytic period, and points toward either increased luteal synthesis or luteal binding of PGF2 alpha during the luteolytic period.

Concentration of prostaglandins in seminal fluid of fertile men

Semen samples from 31 men, all of whom had fathered a child within the preceding year, were analysed for sperm characteristics and for the content of prostaglandins (PGs). Mean concentrations (mg/l) for the four main groups of PGs were 67.1 for PGE, 3.2 for PGF, 245.7 for 19-hydroxy-PGE and 13.3 for 19-hydroxy-PGF. The individual values were distributed over a relatively wide range but the extremely wide ranges reported by previous authors were not confirmed. Information is also presented concerning the relative proportions of the four isomers of PGF, as well as those of 19-hydroxy-PGF. Only sperm density was related to PG concentration in fertile men. Polyzoospermia was associated with a low PGE concentration.

Role of spermine in the cytotoxic effects of seminal plasma

This report further characterizes the cytotoxic properties of seminal plasma and provides evidence for a role of spermine oxidation in the generation of seminal plasma cytotoxicity. Addition of spermine to lymphocyte cultures was found to result in a cytotoxic effect similar to that observed upon addition of seminal plasma. Furthermore, although seminal plasma is not cytotoxic in serum-free medium, addition of monoamine oxidase was sufficient to result in the generation of seminal plasma-associated cytotoxicity. Analysis of 73 individual seminal plasma samples indicated that all were cytotoxic, suggesting that this is an intrinsic property of seminal plasma. These results support a mechanism for seminal plasma cytotoxicity in which oxidation of spermine in seminal plasma by the amine oxidase of fetal calf serum results in generation of a cytotoxic product. It is hypothesized that this product plays a significant role in the phenomenon of seminal plasma immunosuppression. The general application of this principle to other fluids and tissues is discussed.

Simultaneous determination of 6-oxo-prostaglandin F1 alpha and 2,3-dinor-6-oxo-prostaglandin F1 alpha in biological fluids by stable isotope dilution and negative ion chemical ionization mass spectrometry

A stable isotope dilution assay for the simultaneous determination of two metabolites of prostacyclin (1), 6-oxo-prostaglandin F1 alpha (2a) and 2,3-dinor-6-oxo-prostaglandin F1 alpha (3a), in human seminal fluid and human urine is described. A new chemical total synthesis of deuterated internal standard, 18,18,19,19-(2H4)-2,3-dinor-6-oxo-PGF1 alpha (3b), is presented and enables specific and sensitive quantification based on negative ion chemical ionization mass spectrometry. 2a and 3a were analysed as their methoxime pentafluorobenzyl ester tris(trimethylsilyl) ether derivatives in the selected ion monitoring mode registrating the [M-181]- fragments with a detection limit for both prostanoids of 10 pg per injection. The two metabolites occur in human seminal fluid in very low concentrations (2a: 2.8 ng ml-1; 3a: 1.7 ng ml-1) and cannot contribute significantly to the urinary metabolite levels which are in the range of 108-265 ng/24 h for 3a and 124-574 ng/24 h for 2a.

The effect of naproxen on the concentration of prostaglandins in human seminal fluid

Whole ejaculates were examined for their content of prostaglandins (PGs) during medication with 250 mg naproxen three times daily for 2 weeks. Six volunteers delivered semen samples before, periodically during, and after the period of medication. During treatment with naproxen, the concentration of PGE, PGF, 19-hydroxy-PGE, and 19-hydroxy-PGF significantly decreased. One week after cessation of medication the PG concentration had returned almost to that found before treatment. The four 19-hydroxy-PGF compounds could be determined separately and the relation between them estimated. The proportion of 8 alpha-19-hydroxy-PGF2 alpha increased, whereas that of 8 beta-19-hydroxy-PGF1 alpha decreased significantly during the medication period. No significant influence of the treatment on sperm density or motility could be observed. It is concluded that treatment with naproxen, a potent inhibitor of PG synthesis, significantly reduces the concentration of all PGs present in human seminal fluid. The implication of the effect on human fertility is discussed.

The role of prostaglandin E2 in seminal immunosuppression

Seminal plasma, which has high antigenic potential and the capacity to induce immunosuppression, has been incriminated as a possible factor in the acquired immunodeficiency syndrome (AIDS). Seminal plasma contains high concentrations of prostaglandins, which are capable of inducing immunosuppression. As prostaglandin E2 is noted for its immunosuppressive actions, we designed this study to determine whether this prostaglandin is responsible for seminal immunosuppression. Diluted and undiluted samples of semen from 5 heterosexual donors induced a significant suppression of phytohaemagglutinin-stimulated thymidine incorporation into lymphocytes. However, when the prostaglandin E2 levels of the semen samples were extrapolated to a standard prostaglandin E2 dose-response curve, the estimated values did not agree with the prostaglandin E2 levels. We conclude that prostaglandin E2 may contribute to seminal immunosuppression, but is not solely responsible for it.

On the origin of prostaglandins in human seminal fluid

To evaluate the origin of seminal prostaglandins, genital tract fluids were analysed for prostaglandin content in two clinical situations. Six patients delivered semen samples before and after vasectomy. In these patients the prostaglandin concentration remained essentially unchanged although sperm density decreased to zero. In another patient secretory products from the testis and epididymis, and the ejaculate representing mainly the secretion of the seminal vesicles and the prostate gland, were collected separately. Secretions obtained from the testis and epididymis did not contain detectable amounts of prostaglandins, whilst in the ejaculate from the same patient the concentration was within normal limits. The results of the study show that the testis and epididymis do not contribute significantly to the prostaglandin content of human seminal fluid. The previous assumption that the seminal vesicles are the main source of seminal prostaglandins is thus supported.

Eicosanoids in health and in disease: an appraisal

Oxygenation of the 20-carbon polyunsaturated fatty acid, arachidonic acid, which is found in most body cells of all domestic animals, leads to the formation of a group of compounds possessing biological activity. These compounds, collectively known was eicosanoids, currently receive considerable attention owing to their involvement in a wide variety of physiological and pathophysiological processes. Particular interest has been focussed in recent years on the role and control of prostanoids and leukotrienes in inflammatory and allergic conditions in animals and man. Arachidonic acid metabolites are also recognised to be intimately involved in reproductive and perinatal processes; with platelet aggregation and vascular homeostasis; kidney function; fever; certain tumours and many other normal and disease conditions. Eicosanoid research in veterinary medicine is still at a relatively early stage in many respects and in this review an attempt is given to highlight some of the functions of this important series of compounds both in health and in disease. As more evidence comes to light, it is possible that veterinary surgeons may have to consider revising their clinical approach to the treatment of certain disease states where eicosanoids are implicated or where chemotherapy may interfere with their normal physiological activities.

Comparative study of antiinflammatory drugs and sulphasalazine in relation to prostaglandin E and 19 hydroxylated prostaglandin E levels and human male fertility

The effect of lysine salicylate, flurbiprofen and sulphasalazine on human seminal prostaglandin profiles of six normal individuals was studied. All of them were treated with pharmacological doses of the three agents for four days with rest periods of eighteen days in between. Sulphasalazine produced less prostaglandin (PG) inhibition relative to the other two antiinflammatory drugs but in contrast only sulphasalazine induced sperm changes. Infertility status associated with the ingestion of therapeutic levels of sulphasalaziane is not directly related to the endogenous PGEs and 19-OH PGEs, the major prostanoids in human semen. PG determinations were carried out using gas chromatographic (GC) techniques.

The natural variations in prostaglandin concentration in human seminal fluid and its relation to sperm quality*

Prostaglandins E, F, 19-hydroxy E, and 19-hydroxy F (PGE, PGF, 19-OH-PGE, and 19-OH-PGF) in human semen were determined by a new chemical method. The method allows liquefaction to occur, a prerequisite for simultaneous estimation of PG concentration and sperm characteristics in the same ejaculate. The present study showed also that the variation in PG concentration between different individuals was more pronounced than in repeated ejaculates from the same individual. Sperm density and sperm motility seemed related to PG concentration. A high density was associated with a low PG concentration. The concentration of 19-OH-PGE was higher and that of 19-OH-PGF lower in ejaculates with a normal sperm motility than in those with an abnormal motility. It seems that functional requisites of sperm depend upon optimal seminal PG concentration.

Isolation of leukotriene C4 from human seminal fluid

LTC4 was isolated and characterized from seminal fluid of seven human volunteers. A compound with a similar retention time to that of synthetic LTC4 was obtained using reverse-phase high performance liquid chromatography. The ultraviolet absorbance of the extracted substance was identical to synthetic LTC4. Furthermore this compound contracted the guinea pig ileum and lung parenchymal strip. Its effects were antagonized by the leukotriene antagonist FPL55712. It was concluded that LTC4 is present in human seminal fluid in very small amounts (about 100 ng/ejaculate). The possible physiological functions of LTC4 in the reproductive tract are discussed.