Lack of correlation of selenium level in human semen with sperm count/motility

Considering the importance of selenium (Se) in male fertility, its concentration was measured in 211 semen samples from 211 normozoospermic, oligozoospermic, asthenozoospermic, and azoospermic men using the hydride generation atomic absorption spectrophotometry. No significant correlation of any kind existed between Se level in the seminal plasma and sperm count or motility. In view of the known poor correlation of these two frequently used semen parameters with the incidence of pregnancy, the assessment of the fertilizing potential of normozoospermic ejaculates with low Se levels is warranted.     

Seminal plasma proteins and their relationship with sperm motility and morphology in boars

The identification of biomarkers associated with seminal traits could aid in the selection of higher quality ejaculates and benefit the swine industry. The objective of this study was to identify boar seminal plasma proteins associated with sperm motility and morphology. Twenty ejaculates from fifteen adult boars from a commercial boar stud were used for this work. After routine semen collection and analysis, ejaculates were classified into two groups: high‐quality semen (HQS) and low‐quality semen (LQS), based on sperm motility and morphology. Semen samples were processed for seminal plasma separation and analysis by 2D SDS‐PAGE. Total and progressive sperm motility differed between groups (p < 0.001), as well sperm morphology (p < 0.05). The intensity of spots identified as Major seminal plasma PSP‐I (PSP‐I) and cathepsin B (CTSB) was higher in LQS as compared to HQS samples (p < 0.05). Also, PSP‐I was positively associated with major and sperm cauda defects. Sperm motility was negatively correlated with both PSP‐I and cathepsin B. We conclude that high concentrations of Major seminal plasma PSP‐I and cathepsin B in boar seminal plasma are associated with reduced total and progressive sperm motility and low sperm morphology and might be used as biomarkers for semen quality.     

Effects of seminal plasma from normal and asthenozoospermic men on the progressive motility of washed human sperm

Human seminal plasma stimulated the progressive motility of human sperm in a dose- and time-related manner. Serum exhibited a similar capacity for stimulation. Seminal plasma from different normozoospermic men showed marked variation in its capacity to stimulate sperm motility. The stimulatory effect was maintained after heat-treatment, indicating the action of a low molecular weight substance or metal ion. No differences could be observed in the capacity for stimulation between seminal plasma from normozoospermic (n = 23) and asthenozoospermic (n = 22) men, when tested at the same dilution and under identical conditions. It is concluded that in general, differences in seminal plasma composition cannot account for the reduced sperm motility in asthenozoospermic men. Furthermore, the stimulatory effects of seminal plasma may be a property shared by other biological fluids.     

Relationship between Zinc Concentrations in Seminal Plasma and Various Sperm Parameters

The zinc concentration in seminal plasma from 98 infertile male patients and 8 fertile males was measured. The zinc concentration of the seminal plasma in azoospermic and oligoasthenozoospermic patients was significantly lower than that in the other groups (each, p<0.05). The seminal plasma zinc concentration in asthenozoospermic males was significantly higher than that in any other group (p<0.05). There was a positive correlation of zinc concentration with sperm concentration (r=0.33, p<0.05) and with sperm motility (r=0.22, p<0.05), while there was no correlation with sperm morphology. A correlation between zinc concentration and plasma testosterone concentration was observed (r=0.24, p<0.05). It is concluded that excessively high zinc concentration is apparently related to defective motility in asthenozoospermic patients, even though adequate seminal plasma content of the element is required for normal sperm function.     

Metenkephalin in Seminal Plasma of Infertile Men

Background: Enkephalin is one of the opioids, which is expressed widely in reproductive organs. However, the function of enkephalin in male reproduction is not completely understood. The effect of metenkephalin on sperm motility remains especially controversial. In this study we examined the level of metenkephalin in seminal plasma from men with normal sperm production and patients with asthenospermia, oligospermia, and azoospermia to investigate the role of metenkephalin in seminal plasma on sperm function. We also investigated the effect of metenkephalin on sperm motility in vitro.
Methods: Sixty nine infertile patients (31 oligospermic, 21 asthenospermic, and 17 azoospermic) were included in this study. The level of metenkephalin in seminal plasma of these men was measured and the effect of the peptide on the motility of human sperm was examined in vitro. Seventeen men with normal seminograms were a control group.
Results: The level of metenkephalin in the seminal plasma of semen from asthenospermic men was significantly lower than that from the controls ( P < 0.05). No significant correlations between the level of metenkephalin and the mean pathing or progressive velocity of sperm, or serum hormone levels were observed. In the in vitro study, which used semen from the controls, treatment of sperm with metenkephalin (50–200 pg/mL) maintained sperm motility for 4 hours. On the other hand, motility of sperm incubated without metenkephalin began to decrease at 3 hours. Metenkephalin levels of 50 pg/mL in seminal plasma is considered to be necessary for maintaining sperm motility.
Conclusion: These results suggest that metenkephalin in seminal plasma is an important clue in the investigation of decreased sperm motility.     

Seminal plasma vitamin B6 levels in men with asthenozoospermia and men with normal sperm motility,a measurement using liquid chromatography with tandem mass spectrometry

There is growing evidence that vitamin B₆ has a valuable contribution in maintaining normal sperm parameters; however, this contribution has not yet well-identified. Here, we aimed to measure the level of seminal plasma vitamin B₆ in men with asthenozoospermia compared to men with normal sperm motility. Ninety-seven human males with asthenozoospermia and eighty-eight human males with normal sperm motility (control) were recruited in this study. Collected semen samples were assessed for sperm motility, sperm count and semen volume. Liquid chromatography with tandem mass spectrometry was used to measure seminal plasma vitamin B₆ concentrations. A highly significant difference (p < .0001) in concentrations of seminal plasma vitamin B₆ was found between asthenozoospermic and control groups. Besides, no statistical correlations were found between seminal plasma vitamin B₆ level and sperm motility, sperm count, semen volume and men age in both tested groups. In conclusion, men with asthenozoospermia have lower seminal plasma vitamin B₆ level compared to men with normal sperm motility. Also, seminal plasma vitamin B₆ was found not to be correlated with sperm motility and count, semen volume and men age in both tested groups. These results may provide new contribution in the management of male infertility.     

弱精子症、少弱精子症患者血清、精浆和精子锌含量分析

目的:检测弱精子症和少弱精子症患者血清、精浆和精子锌的含量,分析锌含量的变化与精子密度和精子运动之间的关系。方法:按照WHO《人类精液及精子-宫颈粘液相互作用实验室检验手册》第四版的标准进行精液质量分析,随机筛选出90例弱精子症、60例少弱精子症患者以及20例精液质量正常的生育者作为研究对象,利用原子吸收光谱法检测其血清、精浆、精子的锌含量并进行统计学分析。结果:3组间血清锌含量没有显著差异;弱精子症、少弱精子症患者精浆锌含量均显著低于正常生育者(P<0.05);少弱精子症患者精子锌含量显著高于弱精子症患者和正常生育者(P<0.01)。结论:弱精子症、少弱精子症患者精子的发生及运动功能下降可能与精浆锌含量的低下呈正相关;但过高的精子锌含量与精子的发生和运动功能的关系尚不十分明了,有待进一步研究。     

Impact of biological and artificial seminal fluids on sperm parameters and DNA status in asthenozoospermic ejaculates

The chemical composition and physiological properties of seminal fluid (SF) affect sperm quality. The objective was to investigate the effects of in vitro exposure of artificial seminal fluid (ASF) and biological seminal fluid (SF) on sperm quality. Asthenozoospermic ejaculates (n = 20) were divided into two aliquots. The first aliquot was centrifuged for obtaining asthenozoospermic SF. The second aliquot was processed with density gradient centrifugation (DGC), and the pellet was diluted separately with following media: (a) ASF; (b) Ham's F10; (c) normozoospermic SF; and (d) asthenozoospermic SF. Sperm parameters and DNA status were assessed after DGC, as well as 2 and 24 hr after incubation. The data showed that sperm progressive motility, viability and DNA integrity were significantly higher in ASF than Ham's F10 medium immediately after DGC. At 2 and 24 hr, the progressive motility was significantly decreased in biological SF compared with ASF and Ham's F10. DNA fragmentation index (DFI) was significantly lower in normozoospermic SF than asthenozoospermic SF and Ham's F10 at time 2 hr. In conclusion, normal SF showed the protective role on sperm DNA structure. Moreover, ASF preserved sperm motility better than biological SF during 24 hr, despite being similar to normal SF regarding DNA integrity preservation in short time.     

Persistent effects of pentoxifylline on human sperm motility, after drug removal, in normozoospermic and asthenozoospermic individuals

Summary. The aim of the study was to compare the in vitro effect of pentoxifylline on human sperm motility when added prior to sperm selection and the persistence of the response after drug removal in normo- and asthenozoospermic individuals. The sperm samples were obtained from 22 men who were repeatedly asthenozoospermic or normozoospermic. Sperm movement was measured using computer-assisted semen analysis over 180 min. Percentage motility and progressive motility were increased in both normo- and asthenozoospermic samples ( P < 0.05). Curvilinear velocity, amplitude of lateral head displacement and beat-cross frequency were increased in both groups ( P < 0.05). Straight-line velocity was increased significantly in the normozoospermic group only. In both normo-and asthenozoospermic individuals pentoxifylline appeared to enhance sperm motility for at least 180 min after drug removal. This should prevent any potentially toxic effects of the drug on oocytes if it is used to enhance sperm motility during in vitro fertilization.     

Melatonin and Sperm Motility/Melatonin und Spermatozoenmotilität

Several substances can interfere with microtubular function eg. colchicine. Melatonin, a hormone secreted by the pineal gland has similar effects as colchicine on microtubules. In this study melatonin levels were determined in both plasma and seminal plasma of patients with good or impaired motility and forward progression. There was no statistically significant difference between the mean plasma and seminal plasma values of patients with good or impaired motility and forward progression. There was no correlation between seminal plasma melatonin and impaired motility or any other semen parameter. There was also no correlation between plasma and seminal plasma concentrations of melatonin. High seminal plasma melatonin concentrations were not necessarily associated with impaired sperm motility. From these it is concluded that seminal plasma melatonin plays no important role in sperm motility.     

Role of seminal osmolarity in the reduction of human sperm motility

Mammalian sperm at ejaculation are suspended in the seminal plasma, a heterogeneous mixture deriving from the testicular/epididymal fluid and from secretions of seminal vesicles, prostate and bulbourethral glands. Biochemical characteristics of seminal fluid change along the male reproductive tract when considering its inorganic and organic composition and pH but it is known that in each region of the male genital tract seminal osmolarity is higher than that of serum. It has been previously demonstrated that in invertebrate and vertebrate sperm, seminal plasma osmolarity influences sperm motility and activity, and human sperm have been shown to possess osmosensitive calcium entry pathway that controls important functions such as acrosome reaction and oocyte penetration. In the present study, we have determined seminal plasma osmolarity in a large number of normozoospermic fertile and asthenozoospermic infertile subjects correlating it with sperm motility percentages and kinematic characteristics determined utilizing a computerized motion analysis system. Our results confirm that seminal plasma osmolarity is higher than that of serum (336.1 +/- 20.2 vs. 291.1 +/- 6.9 mOsm/L, respectively). Normozoospermic subjects show seminal osmolarity values that are significantly lower with respect to asthenozoospermic patients (317.8 +/- 12.2 vs. 345.2 +/- 22.6 mOsm/L, p<0.001), irrespective of the cause of asthenozoospermia. Seminal plasma osmolarity negatively correlates with sperm progressive motility percentages and kinetic characteristics (curvilinear velocity, linear velocity, linear coefficient and lateral displacements of sperm head). Furthermore, when sperm from fertile subjects were suspended in medium with an osmolarity increasing from 300 to 600 mOsm, sperm motility percentages and kinetics characteristics were progressively reduced and nearly abolished when medium osmolarity was 600 mOsm. On the contrary, when sperm from asthenozoospermic subjects with high semen osmolarity were resuspended in medium with lower osmolarity, sperm motility parameters improved significantly. Sperm motility parameters did not correlate with seminal plasma concentrations of sodium, potassium, chloride with a weak correlation only with seminal calcium concentration. No correlations are present between seminal plasma osmolarity and ionic composition.In conclusion, the present study confirms and extends the knowledge that, in human, seminal plasma osmolarity is higher than that of serum and demonstrates that seminal osmolarity influences sperm motility characteristics and then it may contribute to the pathogenesis of some forms of asthenozoospermia and male infertility.     

Impaired seminal antioxidant capacity in human semen with hyperviscosity or oligoasthenozoospermia.

Antioxidant capacity of seminal plasma was evaluated in 120 semen samples subdivided into asthenozoospermic and oligoasthenozoospermic specimens with normal consistency and into asthenozoospermic and oligoasthenozoospermic specimens with hyperviscosity. Semen samples (n = 25) from normozoospermic donors were used as a control group. Scavenger antioxidant capacity of reactive oxygen species was evaluated by superoxide dismutase and catalase activity measurements, whereas the chain-breaking antioxidant efficiency was detected by total antioxidant status assessment. In semen with normal viscosity, unaltered enzymatic and nonenzymatic antioxidant capacity was revealed in the asthenozoospermic specimens, whereas low superoxide dismutase activity was detected in oligoasthenozoospermic samples. On the contrary, impairment of both the scavenger and chain-breaking antioxidative systems was revealed in asthenozoospermic and oligoasthenozoospermic hyperviscous ejaculates, regardless of sperm count. Catalase activity and total antioxidant status values were also reduced in the 2 subgroups of hyperviscous ejaculates compared with their respective matched controls, whereas similar superoxide dismutase activities were detected in oligoasthenozoospermic samples with normal and high consistencies. These results suggest that asthenozoospermia could be related to an antioxidant deficiency only in combined ejaculate pathologies, and that a severe impairment of the low and high molecular weight seminal antioxidative capacities could be associated with semen hyperviscosity.     

Coenzyme Q10 effect on semen parameters: Profound or meagre?

Coenzyme Q10 has shown promise in treating male infertility; however, there are inconsistencies across the published data. We undertook a quantitative meta-analysis by pooling data from three placebo-controlled randomised clinical trials (RCTs) in order to evaluate the efficacy of CoQ10 in improving semen parameters. Sperm count, sperm motility, sperm forward motility, sperm morphology and CoQ10 level in the seminal plasma were measured and quantitatively correlated with CoQ10 oral administration. Pooled analysis showed a significant impact of CoQ10 in improving sperm motility and forward motility, without a significant impact on sperm count, sperm morphology, ejaculate volume or seminal plasma level of CoQ10. Efficacy assessment suggested that CoQ10 shows better results at higher doses and when administered for a period of more than 3 months but not longer than 6 months. We conclude that CoQ10 has a profound effect on sperm motility and a meagre effect on all other parameters. Therefore, CoQ10 can be used for treating asthenozoospermic infertility with the dosage and duration depending upon the severity of the disorder and the patient's response to the treatment.     

Caffeine increased progressive motility of human spermatozoa in normozoospermic and asthenozoospermic semen samples and enhanced activity of seminal creatine kinase

Even though the effect of caffeine on humans' health has been revealed in various research studies, its effect on semen quality has yet to be well explained. Here, we measured the effect of caffeine at 1, 5, 10 and 20 mM on motility of human spermatozoa in normozoospermic and asthenozoospermic semen samples, level of seminal nitric oxide, chelation of seminal calcium ions and activity of seminal creatine kinase. Fifty-one normozoospermic and ten asthenozoospermic semen samples were recruited in this study. Sperm motility was evaluated by Makler counter, and seminal nitric oxide, seminal-free calcium and activity of seminal creatine kinase were measured spectrophotometrically. Caffeine at 10 mM significantly (p < .05) increased progressive motility of spermatozoa in both tested groups. Also, caffeine significantly increased (p < .05) activity of creatine kinase and insignificantly (p > .05) altered nitric oxide and free calcium levels in seminal plasma. In conclusion, progressive motility of human spermatozoa was found to be higher in the presence of caffeine at 10 mM in normozoospermic and asthenozoospermic semen samples; this increase, albeit partially, could be due to increased activity of seminal creatine kinase, but not to increased production of nitric oxide or chelation of free calcium ions.     

Activity of testis angiotensin converting enzyme (ACE) in ejaculated human spermatozoa

Testicular angiotensin converting enzyme (ACE) isozyme is likely to play important functional roles in male reproduction. Several studies have shown that ACE is released from human spermatozoa during capacitation and that ACE is associated with reduced sperm motility. Recently, we established an assay to detect testicular ACE activity in human spermatozoa. The purpose of this study was to determine if testicular ACE activity is related to sperm motility in human ejaculates. Semen samples were collected from 80 infertile patients. According to the semen characteristics, they were divided into four (WHO) categories. Enzyme activities of ACE in spermatozoa (testicular ACE) and seminal plasma (somatic ACE) were spectrophotometrically determined. Total testicular ACE activity in spermatozoa was measured by solubilization of spermatozoa with Triton X-100. Membrane testicular ACE activity was measured in a sperm : PBS suspension. Sperm concentration and sperm motility were 136.6 +/- 154.1 x 10(6)/mL and 58.6 +/- 23.4%, respectively (mean +/- SD). Enzyme activities of membrane testicular ACE, total testicular ACE and somatic ACE were 0.273 +/- 1.219 microU/10(6) spermatozoa, 0.35 +/- 1.34 microU/10(6) spermatozoa and 684.7 +/- 226.6 mU/mL, respectively. A negative correlation was observed between sperm motility and membrane testicular ACE activity (p < 0.05). Membrane testicular ACE activity in 44 normal semen samples was 0.04 +/- 0.02 microU/10(6) spermatozoa, whilst that in 36 abnormal semen samples was 0.24 +/- 0.42 microU/10(6) spermatozoa. There was a significant difference between these two groups (p < 0.01). Membrane testicular ACE in sperm samples from normozoospermic men was significantly lower than that from oligoasthenozoospermic men (p < 0.05). These findings suggest that testicular ACE is released from normal functional spermatozoa for them to have fertilizing ability.     

Differences in osmolality, pH, buffering capacity, superoxide dismutase and maintenance of sperm motility in human ejaculates according to the degree of coagulation

The purpose of this study was to compare various seminal plasma parameters in fresh human ejaculates exhibiting different amounts of coagulum. Poorly coagulating samples demonstrated significantly lower osmolality and buffering capacity but had a higher pH than did samples with good coagulation. However, no correlation was obtained between the activity of superoxide dismutase and the amount of coagulum. Eight hours after ejaculation, sperm motility had decreased by 15 and 80% in samples with good and poor coagulation, respectively. It is suggested that subfertility may be associated with poor coagulation of ejaculates.     

Seminal plasma nitric oxide concentration in oligo- and/or asthenozoospermic subjects with/without varicocele

There is an inverse correlation between seminal plasma nitric oxide (NO) concentration and sperm parameters (motility and concentration) in patients with varicocele. This study investigated whether this occurs in patients with oligo- and/or asthenozoospermia due to causes other than varicocele. A total of 69 (19 with varicocele and oligo- and/or asthenozoospermia [group 1], 30 from oligo- and/or asthenozoospermic ones without varicocele [group 2], and 20 from healthy subjects [control group]) semen samples were analyzed. While group 1 had a significantly higher NO concentration in the seminal plasma compared to both the control group and group 2, there was no significant difference between group 2 and the control group (p >.05). In group 1, but not in the other groups, there was an inverse correlation between the seminal plasma NO concentration and sperm motility and concentration. NO production could be specifically related to the varicocele, since NO production in oligo- and/or asthenozoospermia cases without varicocele is not increased.     

Immunoreactive relaxin in seminal plasma of fertile boars and its correlation with sperm motility characteristics determined by computer-assisted digital image analysis

Ejaculates from 10 mature fertile large white Yorkshire boars were used to examine the correlation between immunoreactive relaxin levels in seminal plasma and sperm motility characteristics. Seminal plasma levels of immunoreactive relaxin were measured by a time-resolved fluoroimmunoassay (TR-FIA). Motility characteristics were assessed using a CellSoft computer-assisted digital image analysis system. The mean +/- SD level of immunoreactive relaxin in seminal plasma was 2.61 +/- 0.62 ng/mL. When the correlation between seminal plasma levels of immunoreactive relaxin and parameters of sperm movement was examined, it was found that relaxin levels were significantly correlated with the percentage of motile spermatozoa (r=0.687, p < 0.05), curvilinear velocity (r=0.745, p < 0.05), straight line velocity (r=0.651, p < 0.05), mean amplitude of lateral head displacement (mean ALH) (r=0.844, p < 0.01) and the maximum amplitude of lateral head displacement (max ALH) (r=0.830, p < 0.01), but not with linearity, beat-cross frequency, or percentage of circular cells. Among these parameters, seminal plasma levels of immunoreactive relaxin showed the strongest correlation with the ALH parameter related to fertilizing ability. These results indicate that immunoreactive relaxin in boar semen may be necessary not only for normal sperm motility but also for normal fertility, suggesting that determination of the profile of immunoreactive relaxin in ejaculates may have value as a potential marker for predicting sperm fertilizing ability of boars.     

Influence of fibronectin on the motility of human spermatozoa

The objective of the present study was to scrutinize the concentration of seminal fibronectin and the potential effects of exogenous fibronectin on human sperm motility. In addition, variability in the localization of fibronectin on human spermatozoa from andrological patients was studied, at both the light and electron microscopic levels. A total of 58 freshly ejaculated semen samples from patients attending for infertility treatment were submitted to sperm motility analysis and ELISA quantification of seminal plasma and cell-bound fibronectin. Immunofluorescence and immunoelectron microscopy revealed a relatively broad distribution pattern of fibronectin immunoreactivity on sperm heads and testicular spermatids. Addition of a fibronectin antiserum to vital spermatozoa in vitro at a moderate dilution (1:50) resulted in a significant increase in sperm motility. Purified plasma fibronectin, added at various concentrations to a preparation of live spermatozoa, was found to inhibit sperm motility in a dose-dependent manner. At concentrations from 0.18 to 0.5 mg fibronectin per ml ejaculate, no motile spermatozoa were recorded. Seminal plasma fibronectin ranged between 0.8 and 1000 μg/ml in infertility patients. There was a significant inverse correlation between sperm motility and seminal fibronectin in patients with oligo-astheno-teratozoospermia. In a preliminary study in patients with varicocele or hypogonadism, no such correlation was found.     

Seminal immunoreactive relaxin in domestic animals and its relationship to sperm motility as a possible index for predicting the fertilizing ability of sires

Although immunoassayable relaxin has been detected in human and boar seminal plasma, there is no evidence suggesting the existence of immunoreactive relaxin in the seminal plasma of other domestic animals. The first objective of this study was to determine whether immunoreactive relaxin was present in the seminal plasma of bulls, rams and he-goats. In addition, the correlation of immunoreactive relaxin with sperm motility as an index for predicting the fertilizing ability of bull sires was investigated. Semen with normal sperm motility was collected from bulls, rams and he-goats, and the relaxin immunoreactivity of the semen samples was measured using a time-resolved fluoroimmunoassay (TR-FIA) for porcine relaxin that we developed. The presence of relaxin immunoreactivity was demonstrated in seminal plasma from bulls, rams and he-goats. The level of immunoreactive relaxin in seminal plasma was the highest in bulls followed by humans, rams, boars and he-goats in that order, when relaxin levels in boar and human semen having normal sperm motility were also assayed under the same conditions. When the correlation between the seminal plasma level of immunoreactive relaxin and sperm motility was examined in bull semen samples as an index for predicting fertilizing ability, it was found that the relaxin level was significantly correlated with the percentage of spermatozoa showing the most intensive motility (r = 0.64, p < 0.05). These results indicate that immunoreactive relaxin is widely found in the seminal plasma of domestic animals and that measuring the relaxin concentration of seminal plasma may be useful to identify subfertile sires or predict the fertility potential of individual sires.