Effect of l‐arginine addition on long‐term storability of ram semen

This study was conducted to investigate the effect of l ‐arginine addition on long‐term storability of ram semen. Six Akkaraman rams were used as material. Semen samples were collected. Pooled samples were diluted and were divided into six equal aliquots. While aliquot 1 was kept as control, the stock solutions including 0.1, 0.5, 1, 5 and 10 mm l ‐arginine were added to other aliquots. All aliquots were routinely frozen in 0.25‐ml straws at ?130°C liquid nitrogen vapour and stored in liquid nitrogen ?196°C until being analysed. The equilibrated and thawed sperm motility, membrane integrity and arginase activity were evaluated. While the 10 mm l ‐arginine supplementation significantly (p < .001) decreased equilibrated sperm motility, the 5 mm significantly (p < .05) increased the membrane integrity and arginase activity in comparison with the control group. The motility (p < .001) and membrane integrity (p < .01) were determined to be highest in 0.5 mm group, while significant reductions were observed in motility (p < .001) of 10 mm group and arginase activity (p < .05) of 1, 10 mm groups as compared to the control group. It was concluded that in vitro addition of 0.5 mm l ‐arginine to ram semen may be useful, but 10 mm may be harmful to spermatozoa quality during long‐term storage.     

Saturated,omega‐6 and omega‐3 dietary fatty acid effects on the characteristics of fresh,frozen–thawed semen and blood parameters in rams

The aim of this study was to investigate the effects of several dietary fatty acids (FAs) on semen quality and blood parameters in rams. We gave diet‐supplemented treatments (35 g day^?1 ram^?1) by C16:0 (palm oil), C18:2 [sunflower oil (SO)] and an n‐3 source [fish oil (FO)] to 12 rams, who were fed for 15 weeks during their breeding season. Semen was collected once per week. Semen samples were extended with Tris‐based cryoprotective diluents, then cooled to 5 °C and stored in liquid nitrogen. Positive responses were seen with FO after 4 weeks. The mean prefreezing semen characteristics improved with the intake of FO (P < 0.05). Interestingly, maximum sperm output in FO was achieved 7.5 × 10⁹ when compared to palm oil 5.3 × 10⁹. Rams that received FO had the highest total testosterone concentrations (11.3 ng ml^?1 for FO, 10.8 ng ml^?1 for SO and 10.2 ng ml^?1 for palm oil) during the experiment (P < 0.05). FO also improved the rams' sperm characteristics after thawing (P < 0.05). Although C16:0 is a major saturated FA in ram sperm and all rams have been fed isoenergetic rations, the unique FAs of FO improved fresh semen quality and freezing ability compared to other oils.     

Short‐term storage of salmonids semen in a sodium alginate‐based extender

Short‐term storage of semen is a useful strategy for preservation of fish spermatozoa. However, there is a significantly decrease on sperm function mainly due to oxidative stress. In this way, sodium alginate plays an important role as free radical scavenger compound. Accordingly, the aim of our study was to analyse the effect of a sodium alginate‐based extender on sperm function in the short‐term storage of salmonids semen. Samples of Salmo salar, Oncorhynchus kisutch, and Oncorhynchus mykiss were stored in Storfish^® (Ext‐C) and Storfish^® supplemented with sodium alginate (Ext‐A) during 10 days at 4°C. After storage, motility, viability, mitochondrial membrane potential (ΔΨmit), superoxide anion (O₂^?) level and DNA fragmentation (DNA Frag) were assessed. Ext‐A had positive effect in preservation of sperm motility, viability, ΔΨmit, O₂^? level and DNA integrity in the three species analysed compared to control samples. In Ext‐A, the spermatozoa of S. salar and O. mykiss showed significantly higher motility, viability and ΔΨmit than O. kisutch. However, O. kisutch and O. mykiss had significantly lower O₂^? level than S. salar, and DNA fragmentation in O. kisutch and S. salar was significantly lower than in samples of O. mykiss (p < 0.05). Dilution of salmonids semen in a sodium alginate‐based extender is effective for protecting sperm quality during 10 days of short‐term storage.     

Milk,caseinate and lactoferrin addition to equine semen cooling extenders

Cooled semen has been used routinely to prolong sperm viability until artificial insemination time. However, spermatozoa are subjected to oxidative stress. The aim of the present work was to investigate the protective and antioxidant effect of the milk proteins lactoferrin (Lf) and caseinate added to equine semen cooling extenders. Semen from six stallions was cooled at 5 °C after resuspension with C1) milk‐ and glucose‐based, C2) 0.6% caseinate, C3) C2 + Lf 200 μg ml^?1, C4) C2 + Lf 500 μg ml^?1 and C5) C2 + Lf 1000 μg ml^?1 extenders, and kept at 5 °C for 24 h. Sperm motility characteristics and intact membrane rates were not different among the treatments (P > 0.05). As a result of the cooling process, the nitrite concentration increased significantly in the cooled semen (69.6 ± 78.9 μm per ×10⁶ spermatozoa) compared with the fresh semen (8.6 ± 1.9 μm per ×10⁶ spermatozoa). In contrast, the H₂O₂ concentrations were lower in the 0.6% caseinate extender (265.9 ± 221.3 μm per ×10⁶ spermatozoa) than in the milk extender (430.9 ± 199.8 μm per ×10⁶ spermatozoa, P < 0.05), showing an antioxidative effect of the caseinate compared with the milk. However, in all groups, hydrogen peroxide concentrations were similar to the undiluted fresh semen (332.8 ± 151.3 μm per ×10⁶ spermatozoa). Caseinate showed to be as efficient as milk to protect equine‐cooled spermatozoon.     

Correlation between lead and cadmium concentration and semen quality

There are contrary reports of association of lead and cadmium with the decline in semen quality. This study evaluates whether seminal lead (Pb) and cadmium (Cd) at environmental concentration are associated with altered semen quality. We conducted a study of healthy fertile and infertile men 20–43 years of age attending the Andrology Laboratory of Reproductive Biology Department for semen analysis. The semen analysis was carried out according to the WHO 2010 guidelines. Seminal lead and cadmium were estimated by ICP‐AES. The lead and cadmium values were significantly higher in infertile subjects. A negative association between seminal lead or cadmium concentration and sperm concentration, sperm motility and per cent abnormal spermatozoa was found. This study shows that exposure to Pb (5.29–7.25 μg dl^?1) and cadmium (4.07–5.92 μg dl^?1) might affect semen profile in men. Age, diet, smoking and tobacco chewing habits may have an influence on the increase in exposure to Pb and Cd in the individual subjects.     

Selenium and vitamin E supplementation enhances the antioxidant status of spermatozoa and improves semen quality in male dogs with lowered fertility

Studies showed a beneficial effect of supplementation with selenium (Se) and vitamin E on semen quality. The aim of the study was to investigate the effect of Se and vitamin E supplementation on the antioxidant status of spermatozoa and semen quality in dogs with lowered fertility. Ten dogs were supplemented daily with Se (6 μg/kg organic Se yeast) and vitamin E (5 mg/kg) per os for 60 days. Control group consisted of 10 males without the supplementation. Semen was collected on day 0, 30, 60 and 90. Sperm quality parameters were evaluated using CASA and a microscope. Concentrations of Se and vitamin E in blood as well as glutathione peroxidase (GSH‐Px) activity and total antioxidant capacity (TAC) in the spermatozoa were determined. After 60 days of supplementation the concentration of spermatozoa, the majority of motility indicators and the percentage of normal morphology and live spermatozoa increased significantly (p < .05). An increase (p < .05) in concentration of Se and vitamin E in blood and GSH‐Px‐activity and TAC in the spermatozoa was detected. The study results indicate that Se and vitamin E supplementation for 60 days enhances the antioxidant status of spermatozoa and improves the quality of the semen in dogs with lowered fertility.     

The correlates and alleged biochemical background of the resazurin reduction test in semen

Reduction of the blue dye resazurin to pink resorufin is used to estimate the concentration of metabolically active spermatozoa in semen samples. In order to quantify the reduction of resazurin, a spectrophotometric method was developed measuring the change from blue to pink in the butanol extracted colour. The biochemical mechanisms involved in the reduction of resazurin by motile spermatozoa and seminal plasma were investigated. Addition of NADH + H⁺ to sperm suspension or seminal plasma increased the reduction of resazurin. The reduction reaction was inhibited by high concentrations of dicoumarol, a specific inhibitor of the diaphorase enzyme, in a dose-dependent manner. It is suggested that the sperm diaphorase enzyme transfers electrons from NADH + H⁺ to resazurin, reducing it to resorufin.
The degree of resazurin reduction was strongly correlated with the concentration of motile spermatozoa recovered from the 90% Percoll fraction ( r  = 0.98, p  < 0.001). A positive correlation was also found between the reducing capacity of seminal plasma ( n  = 62) on the one hand, and sperm concentration ( r  = 0.72, p  < 0.0001), progressive motility ( r  = 0.45, p  < 0.01), normal morphology ( r  = 0.50, p  < 0.01), and γ-glutamyltransferase ( r  = 0.36, p  < 0.05) on the other hand.
These findings, together with our previous observations that the reduction reaction is inhibited by reactive oxygen species and polymorphonuclear white blood cells, increase our understanding of the biochemical basis of the resazurin test and may provide better insight into the interpretation of this test.     

Survival of buffalo bull spermatozoa: effect on structure and function due to alpha‐lipoic acid and cholesterol‐loaded cyclodextrin

Sperm survival depending upon integral membranes and function is imperative for fertilization. This study was designed to augment survival of buffalo spermatozoa using alpha‐lipoic acid (ALA) and cholesterol‐loaded cyclodextrin (CLC) during cryopreservation. Semen was frozen using 0, 0.5, 1, 1.5, 2 and 2.5 mmol L^?1 ALA (experiment 1) and ALA or CLC separately or together (experiment 2). Semen was assessed for post‐thaw motility, plasma membrane integrity (PMI), intact acrosome and plasma membrane (IACR‐IPM) and DNA integrity at 0, 1.5, 3 and 4.5 hr of incubation. In experiment 1, use of 0.5 mmol L^?1 ALA enhanced the sperm cryosurvival and post‐thaw longevity than other groups up to 4.5 hr of incubation, and this concentration of ALA was used in second experiment with CLC. The results revealed higher (p < .05) sperm survival function and time of sperm attributes due to use of ALA than CLC and control. However, the sperm quality did not improve (p > .05) when ALA was combined with CLC. In conclusion, survival of buffalo bull spermatozoa during freeze‐thawing and post‐thaw incubation can be enhanced more with ALA than CLC or control, followed by CLC than control. However, there is no synergistic effect on survival of buffalo bull spermatozoa due to ALA and CLC.     

Relationship between human spermatozoa–hyaluronan‐binding assay,conventional semen parameters and fertilisation rates in intracytoplasmic spermatozoa injection

Selecting the best spermatozoa for intracytoplasmic spermatozoa injection (ICSI) has recently been a topic of great interest among embryologists. The study aimed to evaluate the relationship between the spermatozoa‐hyaluronan‐binding assay (HBA), routine semen analysis results and fertilisation rates as recorded during conventional ICSI therapy. Ninety‐one patients undergoing conventional ICSI treatment in the Medfem Fertility Clinic in Johannesburg (South Africa) were included in the study. A total of 797 oocytes were injected of which 457 oocytes fertilised (57.3%, range 0–100%). None of the semen parameters correlated with the fertilisation rates (Table 2). HBA scores, however, revealed a highly significant association (p ≤ 0.0001) with the fertilisation rates. The HBA scores also correlated significantly with the biochemical pregnancy values (Spearman r = 0.24, P = 0.02, 95% CI 0.039–0.43); however, the HBA scores did not correlate with the clinical pregnancy rates (Spearman r = 0.14, P = 0.16, 95% CI ?0.06 to 0.34). No correlation was recorded between HBA and the standard semen parameters. The study showed that HBA is significantly associated with fertilisation in conventional ICSI. The HBA scores were also significantly associated with the fertilisation rates and biochemical pregnancies.     

Correlation of biochemical constituents of seminal plasma with semen quality in Teddy goat (Capra hircus) bucks

This study was planned to determine the relationship between semen quality parameters and the levels of biochemical constituents of seminal plasma of Teddy (Capra hircus) buck semen. For this purpose, semen ejaculates were collected from five mature healthy Teddy bucks. All the experimental bucks were kept under natural environmental conditions. Semen was collected twice in a week for the duration of 6 weeks by Artificial Vagina (AV) in the breeding season (February‐April). Two successive ejaculates of single buck were pooled at time of collection, and a total of 60 semen samples were processed for semen analysis. Sperm per cent motility, sperm concentration, dead sperm percentage, morphological abnormal spermatozoa, plasma membrane integrity were correlated with biochemical constituents of seminal plasma. The mean per cent motility (89.18% ± 0.37%), sperm concentration (1.86 ± 0.04 × 10⁹/ml), dead sperm percentage (8.08% ± 0.29%), morphological abnormal spermatozoa (6.05% ± 0.29%) and plasma membrane integrity (88.22% ± 0.34%) were recorded. The seminal plasma contained Na⁺ (144.12 ± 1.59 mEq/L), K⁺ (27.38 ± 0.49 mEq/L), Cl^? (65.73 ± 0.45 mEq/L), Ca⁺⁺ (9.34 ± 0.22 mg/dl), P (19.32 ± 0.97 mg/dl), aspartate aminotransferase (AST; 26.48 ± 1.30 IU/L), alanine aminotransferase (ALT; 168.47 ± 5.18 IU/L), lactate dehydrogenase (LDH; 215.98 ± 6.06 IU/L), albumin (1.90 ± 0.10 g/dl), globulins (2.08 ± 0.11 g/dl) and total protein (3.98 ± 0.20 g/dl). The collected data were analysed by applying Pearson's correlation coefficients. Dead sperm percentage had negative correlation with sodium (r = ?.278, p < .05), albumin (r = ?.294, p < .05), globulin (r = ?.266, p < .05) and total protein (r = ?.295, p < .05). Phosphorus was negatively associated with sperm concentration (r = ?.262, p < .05). AST was negatively correlated with plasma membrane integrity (r = ?.292, p < .05). It was concluded that most of the semen quality parameters of Teddy bucks were positively correlated with biochemical constituents, but opposite trends were found in case of dead sperm percentage. The seminal biochemical constituents dynamically interact with each other.     

The micronutrient supplements,zinc sulphate and folic acid,did not ameliorate sperm functional parameters in oligoasthenoteratozoospermic men

We investigated the effects of folic acid and zinc sulphate supplementation on the improvement of sperm function in subfertile oligoasthenoteratozoospermic (OAT) men. Eighty‐three OAT men participated in a 16‐week intervention randomised, double‐blind clinical trial with daily treatment of folic acid (5 mg day^?1) and zinc sulphate (220 mg day^?1), or placebo. Before and after treatment, semen and blood samples were obtained for determining sperm concentration, motility, and morphology, sperm viability, sperm mitochondrial function, sperm chromatin status using toluidine blue, aniline blue, acridine orange and chromomycin A₃ staining; and semen and blood folate, zinc, B₁₂, total antioxidant capacity ( TAC) and malondialdehyde (MDA) concentrations. Sperm concentration (×10⁶ ml^?1) increased in subfertile men receiving the combined treatment of folic acid and zinc sulphate and also in the group receiving only folic acid treatment; however, it was not statistically significant (P = 0.056 and P = 0.05, respectively). Sperm chromatin integrity (%) increased significantly in subfertile men receiving only zinc sulphate treatment (P = 0.048). However, this improvement in sperm quality was not significant after adjusting placebo effect. This study showed that zinc sulphate and folic acid supplementation did not ameliorate sperm quality in infertile men with severely compromised sperm parameters, OAT. Male infertility is a multifactorial disorder, and also nutritional factors play an important role in results of administration of supplementation on sperm parameters. However, these results should be confirmed by multiple studies in larger populations of OAT men.     

Utilisation of sperm‐binding assay combined with computer‐assisted sperm analysis to evaluate frozen‐thawed bull semen

Due to homologies between the chicken egg perivitelline membrane with mammalian zona pellucida proteins, spermatozoa of several species are able to bind to this membrane. However, adequate standardisation is required to attest possible applications of this technique for semen evaluation of a given species. Therefore, we thawed and divided cryopreserved semen samples into two aliquotes, one kept in water bath at 37 °C (thawed) and the other submitted to snap‐freezing to damage sperm cells (dead spermatozoa). Aliquotes were mixed into different ratios of thawed:dead cells and analysed for motility, membrane and acrosomal integrity, and mitochondrial activity. In parallel, chicken egg perivitelline membranes were inseminated with these ratios, and the number of spermatozoa bound per mm² of membrane was assessed by conventional microscopy (CM) and computer‐assisted sperm analysis (CASA). Linear regression showed high correlation between thawed:dead sperm ratio and number of spermatozoa bound to the membrane (CM: r² = 0.91 and CASA: r² = 0.92 respectively). Additionally, positive correlations were found between the number of spermatozoa bound to the membrane and acrosomal integrity, membrane integrity, mitochondrial activity and motility. These findings indicate that sperm‐egg‐binding assay associated with CASA is a reliable, practical and inexpensive method for examining the fertilising capacity of cryopreserved bull semen.     

Antioxidant effect of lemon balm (Melissa officinalis) and mate tea (Ilex paraguensys) on quality,lipid peroxidation and DNA oxidation of cryopreserved boar epididymal spermatozoa

In this study, we investigated the protective ability of the addition of two antioxidant herb extracts, mate tea and lemon balm, on boar epididymal frozen–thawed spermatozoa quality. Testes from mature boars were collected at local slaughterhouse, and sperm samples from epididymis were recovered by flushing. Spermatozoa were cryopreserved in lactose–egg yolk buffer supplemented with various concentrations of lemon balm and mate tea (0, 2.5, 5 and 10 g l^?1) using the straw‐freezing procedure. Motion parameters, acrosome and plasma membrane integrity, lipoperoxidation levels and DNA oxidative damage (8‐hydroxy‐2′‐deoxyguanosine base lesion) were evaluated. There were no differences among experimental groups with regard to motility characteristics, viability, acrosome and plasma membrane integrity; however, the highest concentration of lemon balm produced significant (P < 0.05) improvement in curvilinear trajectory, straightness and amplitude of lateral head displacement after thawing. The supplementation of freezing extender with mate tea and lemon balm reduced sperm lipid membrane peroxidation, and only mate tea protected DNA against oxidative damage during cryopreservation at 120 min post‐thawing (P < 0.05). Mate tea experimental extender at concentration of 10 g l^?1 showed the lowest percentage of sperm oxidised DNA and malondialdehyde generation; thus, mate tea is a potential candidate such as antioxidant compound on boar sperm cryopreservation medium.     

Boar sperm quality after supplementation of diets with omega‐3 polyunsaturated fatty acids extracted from microalgae

This study evaluated effects of diet supplementation with omega‐3 polyunsaturated fatty acids (PUFA) from microalgae on boar sperm quality. Two groups of boars (n = 3 each) were fed during 75 days either a commercial diet (control), or the same diet supplemented with omega‐3 PUFA from the heterotrophic microalgae Schizochytrium sp. (120 g/kg). Sixteen ejaculates were collected per boar. Some sperm kinetics parameters were inferior for supplemented than for control boars (p < .05): distance average path; distance in both curved and straight line; velocity average path, velocity in both curved and straight line; and amplitude of lateral head displacement. Spermatozoa from supplemented boars presented lower mitochondrial functionality, but greater membrane fluidity compared to the control group (p < .01). Membrane and acrosome integrity, production of reactive oxygen species and lipid peroxidation did not differ (p > .05). Serum cholesterol levels were greater (p < .05) for supplemented than for control boars at the 30th and 60th d of supplementation, but levels of triglycerides and IGF‐1 did not differ (p > .05). Compared to the control, spermatozoa of supplemented boars were slower, travelled shorter distances and presented impaired energy metabolism, but their greater membrane fluidity may potentially favour their cryopreservation.     

Organic selenium supplementation increases PHGPx but does not improve viability in chilled boar semen

This study evaluated the effects of dietary organic selenium (Se) on viability of chilled boar semen. Twelve boars were divided into three groups: control (CON), 0.3 mg kg^?1 sodium selenite; inorganic (INO), 0.5 mg kg^?1 sodium selenite and organic (ORG), 0.5 mg kg^?1 Se yeast. The experiment was conducted within 10 weeks, and analysis was performed fortnightly, in storage semen by 72 h. No effect was observed on motility; however, straightness and linearity percentages were higher (P < 0.05) in the animals receiving CON diet compared with INO group. Percentages of cells with both plasma and acrosomal intact membranes, lipidic membrane peroxidation and mitochondrial membrane potential were similar on all treatments. Animals receiving CON diet presented higher (P < 0.05) values of ATP when compared with INO group. The PHGPx was higher (P < 0.05) in animals that received ORG in comparison with INO group. In conclusion, organic selenium supplementation increases PHGPx but does not improve chilled semen viability in 72 h.     

Antioxidative effects of cysteamine,hyaluronan and fetuin on post‐thaw semen quality,DNA integrity and oxidative stress parameters in the Brown Swiss bull

The aim of this study was to compare the effectiveness of antioxidants including cysteamine (2.5, 7.5 mm ), hyaluronan (0.25, 1 mg ml^?1) and fetuin (5, 10 mg ml^?1) in the freezing of Brown Swiss bull semen. The best percentages of CASA motilities were achieved with 10 mg ml^?1 of fetuin and 2.5 mm of cysteamine. For sperm morphology, 10 mg ml^?1 of fetuin and 2.5 mm of cysteamine had better protective effects (P < 0.001). The results of hypo‐osmotic swelling test showed that the percentage values of membrane integrity in all the groups, excluding that supplemented with 5 mg ml^?1 of fetuin, were higher than those of the control group (P < 0.001). Results obtained for the DNA damage of sperm cells demonstrated that 0.25 mg ml^?1 of hyaluronan, and 2.5 and 7.5 mm of cysteamine led to lower rates of spermatozoa with damaged DNA, compared with the control group (P < 0.001). The maintenance of superoxide dismutase and glutathione peroxidase antioxidant activities following freeze‐thawing with 2.5 and 7.5 mm of cysteamine and 10 mg ml^?1 of fetuin was demonstrated to be at a higher level in comparison with the control group (P < 0.001). Malondialdehyde formation was found to be lower in the groups supplemented with 0.25 mg ml^?1 of hyaluronan and 7.5 mm of cysteamine after the freeze‐thawing process (P < 0.001).     

Effects of season on boar semen parameters and antioxidant enzymes in the south subtropical region in Brazil

Although boar semen productivity is affected by seasonality, its effects are not equal among different regions which raise concerns regarding the profitability of boar stud farms. Therefore, the goals of this study were (i) to evaluate the seasonal effect on semen production in a commercial boar stud farm located in a subtropical climate region and (ii) to verify whether the activities of superoxide dismutase and glutathione peroxidase in spermatozoa and seminal plasma were associated with seminal traits of fresh and cooled semen. Nine boars were collected twice per season, and routine seminal parameter analyses were performed together with superoxide dismutase and glutathione peroxidase activities in seminal plasma and spermatozoa. Despite a reduction in sperm concentration in spring and summer, most seminal parameters were constant year‐round. Temperature–humidity index was higher in the summer compared to spring, autumn and winter (p < .05). Superoxide dismutase activity in spermatozoa was increased in summer compared to autumn and winter (p < .05). The activities of both enzymes in seminal plasma and spermatozoa glutathione peroxidase remained unaltered throughout the seasons. In conclusion, seasonality showed little influence in overall boar seminal parameters despite microclimatic differences among seasons, and spermatozoa collected during summer increased superoxide dismutase activity.     

Relationship of seminal reactive nitrogen and oxygen species and total antioxidant capacity with sperm DNA fragmentation in infertile couples with normal and abnormal sperm parameters

The objective of this study was to investigate the association between the amount of superoxide anion, peroxynitrite as oxidative stress (OS) markers and total antioxidant capacity (TAC) with sperm DNA fragmentation in infertile men with abnormal semen parameters. Semen samples were obtained from 102 infertile couples and divided into groups with normal and abnormal semen parameters according to the World Health Organization (WHO). Peroxynitrite and superoxide anions were detected using spectrofluorometric assays combined with 2,7 dicholorofluorescein (DCF)‐DA and 4‐chloro‐7‐nitrobenzo‐2‐oxa ‐1, 3‐diazole (NBD‐CL). Colorimetric assay was used for evaluation of TAC, while DNA fragmentation was studied by using sperm chromatin dispersion test. Superoxide anion, peroxynitrite and DNA fragmentation were significantly higher in infertile couples with abnormal semen parameters as compared to infertile couples with normal semen (P < 0.01). TAC was significantly lower in infertile men with abnormal semen parameters (P < 0.01). There was also a significant positive correlation between OS markers with sperm DNA fragmentation (r = 0.59, P < 0.01 and r = 0.67, P < 0.01, respectively). We have found that imbalance between superoxide anion and peroxynitrite with antioxidant capacity in infertile men with abnormal sperm parameters is associated with higher sperm DNA fragmentation.     

DNA hydroxymethylation rate in the AChE and HoxC4 promoter associated with human sperm quality

The relationship of altered DNA 5′‐hydroxymethylation in human spermatozoa with seminal parameters remains unclear. The aim of the study was to investigate the association between the 5′‐hydroxymethylcytosine (5hmC) rate in the promoters of acetylcholinesterase (AChE) and homeobox C4 (HoxC4) genes and human sperm concentration/motility. The study population consisted of three groups: asthenozoospermia (AZ), oligoasthenozoospermia (OAZ) and normozoospermia (NZ). The 5hmC rate in the promoter was measured by CCGG loci‐dependent MspI/HpaII restriction mapping of glycosylation‐modified sperm DNA combined with a hydroxymethylation‐specific real‐time polymerase chain reaction assay. The 5hmC rate in the AChE promoter in group AZ and OAZ was higher than that in group NZ (p < .05). A weak inverse correlation between 5hmC rate of AChE and sperm motility was observed in all subjects (r = ?.172, p < .05). The 5hmC rate in the HoxC4 promoter in group OAZ was lower than that in group NZ (p < .05). These results indicated that altered 5hmC rates of AChE and HoxC4 promoters are associated with low sperm motility and sperm concentration respectively.