Seminal Plasma Glutathione Peroxidase Activity Research Articles

Hydroxy-selenomethionine as an organic source of selenium in the diet improves boar reproductive performance in artificial insemination programs.

This study aimed to compare different selenium (Se) sources in the diet on boar's semen quality and fertility. For this, 28 boars aged 8 to 28 mo were fed with the following dietary treatments for 95 d: 0.3 mg Se/kg as sodium selenite (SS; n = 14) and 0.3 mg Se/kg as hydroxy-selenomethionine (OH-SeMet; n = 14). During this period, two experiments were carried out. In experiment 1, the semen of all boars was evaluated every 2 wk. Raw semen was initially evaluated for the processing of seminal doses, which were stored at 17 °C for 72 h, followed by sperm quality assessments. Furthermore, Se concentration and glutathione peroxidase (GPx) activity were measured in the seminal plasma. In experiment 2, 728 females were inseminated weekly with seminal doses from boars of the different experimental groups to further assess in vivo fertility and litter characteristics. Results demonstrated that boars fed OH-SeMet had more Se in their seminal plasma (P < 0.05), showing the greater bioavailability of the organic source in the male reproductive system. Moreover, boars fed OH-SeMet tended (P < 0.10) toward a higher total sperm count in the ejaculate (66.60 vs. 56.57 × 109 sperm) and the number of seminal doses (22.11 vs. 18.86; 3 × 109 sperm/dose) when compared with those fed SS. No effect of the dietary treatments was observed on GPx activity in seminal plasma (P > 0.05) as well as on raw and stored semen quality (P > 0.05). Under in vivo conditions, seminal doses from boars fed OH-SeMet tended (P < 0.10) toward a higher pregnancy rate at weeks 3, 5, and 8, and also resulted in a higher (P < 0.05) percentage of pregnant females in the overall period (99.30 vs. 97.00). In conclusion, the replacement of SS with OH-SeMet in boars' diet can improve sperm production and results in better reproductive performance for them, bringing greater productivity and profitability to artificial insemination centers and commercial pig farms.

Effects of feeding 60% dried corn distillers grains plus solubles or the equivalent sulfur as CaSO4 on performance and reproductive traits of yearling Angus bulls

The objectives of this study were to investigate the effects of feeding 60% dried corn distillers grains plus solubles (DDGS) or the equivalent sulfur as calcium sulfate (CaSO4) on semen quality and performance characteristics in yearling bulls. Thirty-six half-sibling Angus bulls [291 ± 8.5 d; initial body weight (BW) = 320 ± 2.7 kg] were assigned to one of three diets: 1) 60% concentrate as corn (CON; S = 0.18%; n = 12); 2) 60% DDGS replacing corn (60DDGS; S = 0.55% DM; n = 12); 3) CON + equivalent sulfur of 60DDGS added as CaSO4 (SULF; S = 0.54%; n = 12). Bulls were fed for 112 d to target an average daily gain (ADG) of 1.6 kg/d. Blood samples were collected on d 0, 56, and 112, and evaluated for testosterone, thyroxine, triiodothyronine (T3) and glutathione peroxidase (GPx) activity. Ruminal H2S was measured on d 0, 14, and 42. Scrotal circumference and semen were collected on d 0, 28, 56, 84, and 112 to evaluate sperm characteristics and GPx activity in seminal plasma. A computer assisted semen analysis was used to evaluate kinematic profiles in motile and progressive sperm throughout the study. Data were analyzed as repeated measures using MIXED procedures of SAS. No differences (P ≥ 0.14) were observed for final BW, ADG, or scrotal circumference; however, SULF tended (P = 0.07) to have reduced gain:feed compared with CON, with 60DDGS being intermediate. Concentrations of ruminal H2S on d 42 were greatest (P < 0.01) for SULF. Increased ejaculate volume was observed for 60DDGS and CON (P < 0.01) compared with SULF. For motile populations of sperm, velocity on an average path (VAP) and curvilinear velocity (VCL) were reduced (P ≤ 0.02) for SULF compared with CON, with 60DDGS being intermediate. In progressively motile sperm throughout the study, VAP and VSL were reduced (P ≤ 0.05) in 60DDGS and SULF compared to CON. For VCL, SULF was reduced (P ≤ 0.02) compared with CON, with 60DDGS being intermediate. In serum, concentrations of T3 were reduced (P = 0.009) in 60DDGS compared with CON or SULF. A treatment by day interaction (P = 0.03) was observed for seminal plasma GPx. At d 56, GPx activity was greater (P = 0.03) for 60DDGS compared with CON, with SULF intermediate; and at d 112, 60DDGS had the greatest (P ≤ 0.02) GPx activity. Therefore, feeding 60% DDGS to developing bulls altered semen kinematics, T3 concentrations, and GPx activity leading to the conclusion that these differences may not be solely dependent on concentrations of dietary sulfur.

35 Effect of feeding 60% dried corn distillers grains plus solubles or the equivalent sulfur on performance, hormone concentrations, and glutathione peroxidase activity in yearling Angus bulls

Abstract The objectives were to investigate the effects of feeding 60% dried corn distillers grains plus solubles (DCD) or equivalent sulfur as calcium sulfate (CaSO4) on performance, hormone concentrations, and glutathione peroxidase (GPx) activity in yearling bulls. Thirty-six half-sibling Angus bulls [256 ± 8 d; initial BW = 320 ± 2 kg] were assigned one of three treatments: 1) corn-based diet containing 60% concentrate (CON; S = 0.18%; n = 12); 2) diet containing 60% DCD as a replacement for corn (DDGS; S = 0.53% DM; n = 12); 3) CON diet + equivalent sulfur of the DDGS diet added as CaSO4 (SULF; S = 0.51%; n = 12). Bulls were fed in Calan gates to target an average daily gain (ADG) of 1.6 kg/d. Data were analyzed as repeated measures using PROC MIXED in SAS. Blood and semen samples were collected on d 0, 56, and 112 then evaluated for concentrations of testosterone, thyroxine, triiodothyronine in serum, and GPx activity in seminal plasma. By design, no differences (P ³ 0.14) were observed among treatments for final BW, ADG or dry matter intake. However, DDGS tended (P = 0.07) to have reduced gain: feed when compared with CON, whereas SULF was intermediate. No differences (P ³ 0.13) were observed among treatments for serum concentrations of testosterone and thyroxine; however, DDGS had reduced (P = 0.009) triiodothyronine concentrations compared with CON and SULF. A treatment ′ d interaction (P = 0.03) was observed for seminal plasma GPx. On d 56, GPx activity was greater (P = 0.03) for DDGS compared with CON, whereas SULF was intermediate, but on d 112, DDGS had greater (P £ 0.02) GPx activity compared with CON and SULF. Therefore, alterations in triiodothyronine concentrations and GPx activity among treatments indicates that DDGS may influence characteristics of semen quality.

Impact of seminal plasma superoxide dismutase and glutathione peroxidase on cryopreserved buffalo spermatozoa

Fifty semen samples were collected from sixteen buffalo-bulls (4–10 years old) and evaluated before cryopreservation. The activity of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) as well as the levels of glutathione (GSH) and malondialdehyde (MDA) were assayed in the seminal plasma before freezing. Aspartate aminotransferase (AST) activity and cholesterol content were assayed in seminal plasma before freezing and after thawing. Results revealed the presence of SOD and GPx activities (0.07±0.01U/ml and 14.59±0.50nmol/min/ml, respectively) in buffaloes’ seminal plasma. SOD activity was positively correlated with both of GSH level and GST activity in seminal plasma, and showed an inverse relationship with both cholesterol efflux and post-thaw abnormal tails of buffalo spermatozoa. A positive correlation was found between GPx activity in seminal plasma and abnormal tails and an inverse relationship with both post-thaw viability indices and increased motility in response to PTx. GST activity showed a positive correlation with the increased motility after addition of PTx and negative correlations with both of cholesterol level and AST activity. MDA levels were negatively correlated with motility after addition of PTx and positive correlations with both post-thaw abnormal acrosomes and tails. Buffalo seminal plasma contains high activities of SOD, GPx and GST enzymes and GSH levels that have an influence on the functional competence of cryopreserved spermatozoa.

Vitamin E and organic selenium enhances the antioxidative status and quality of chicken semen under high ambient temperature

1. The effects of supplemental dietary vitamin E and organic selenium (Se), and their combination, on improving semen quality characteristics and antioxidative status were investigated in cockerels exposed to high ambient temperature. 2. A total of 36 Egyptian local cross males, 40 weeks old, were housed individually in cages in an open-sided building (average daily temperature ranged from 33 to 36°C and relative humidity from 60 to 70%). Birds were divided randomly into 4 experimental treatments (n = 9 each): (1) control (basal diet without any supplementation with vitamin E or Se); (2) vitamin E (basal diet +200 mg α-tocopherol acetate/kg diet); (3) Se (basal diet +0·3 mg organic Se/kg diet); and (4) vitamin E + Se (basal diet +200 mg α-tocopherol acetate/kg diet +0·3 mg organic Se/kg diet). 3. Under heat stress conditions, inclusion of vitamin E and/or organic Se in the diets enhanced the semen quality traits, including the spermatozoa count and motility, and reduced the percentage of dead spermatozoa. 4. A combination of 200 mg/kg vitamin E with 0·3 mg/kg organic Se reduced the thiobarbituric acid reactive substance concentration in seminal plasma samples to about 28% of the controls; and also enhanced the seminal plasma glutathione peroxidase activity by two-fold compared with controls. 5. It was concluded that dietary vitamin E in combination with organic Se has a synergistic effect in minimising lipid peroxidation and improving the antioxidative status in seminal plasma of the domestic fowl, which probably translated into enhanced spermatozoa count, motility and reduced percentage of dead spermatozoa under heat stress conditions.

Glutathione peroxidase activity in seminal plasma and its relationship to classical sperm parameters and in vitro fertilization-intracytoplasmic sperm injection outcome

To relate the glutathione peroxidase (GPX) activity level in human seminal plasma with standard semen parameters and spermatozoa fertilization potential in terms of fertilization and pregnancy rates in an IVF program. Prospective study. Human Reproduction Unit at Cruces Hospital (Vizcaya, Spain). Three hundred consecutive males from infertile couples participating in the IVF program. None. Analysis of GPX activity in seminal plasma by spectrophotometry. GPX activity in seminal plasma was significantly lower in patients with abnormal sperm as assessed by 1999 and 2010 World Health Organization (WHO) criteria, compared with normozoospermic individuals. There was a more significant decrease in those samples with severe sperm pathologies. GPX values were significantly lower in samples with severe asthenozoospermia, oligozoospermia, and teratozoospermia compared with normal samples. However, there was no correlation between GPX activity in seminal plasma in IVF patients and fertilization rates or pregnancy outcome. Although seminal plasma GPX activity was related to semen quality according to WHO parameters, such an association was not found with IVF-intracytoplasmic sperm injection (ICSI) outcome, presumably because of the well-known ability of IVF-ICSI procedures to overcome sperm deficiencies in the fertilization process.

Relationship between seminal antioxidant enzymes and the phospholipid and fatty acid composition of spermatozoa

Sperm cell membranes are susceptible to peroxidative damage through an excess of reactive oxygen species. The objective of this study was to determine seminal plasma glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity and relate these to phospholipid profiles and phospholipid-esterified fatty acid composition of spermatozoa. Seminal plasma GPX and SOD activity, phospholipid, phospholipid-esterified fatty acid composition and malondialdehyde (MDA) of spermatozoa were assayed in 10 normozoospermic and 25 asthenozoospermic subjects. Mean seminal GPX and SOD activity in normozoospermic men were not significantly different from asthenozoospermic men. A significant positive correlation was observed between seminal plasma GPX activity and phosphatidylcholine content ( r = +0.77, P = 0.037) and there was a significant negative correlation with lysophosphatidylcholine content ( r = −0.89, P = 0.02) in normozoospermic sperm samples. Positive correlations were found between SOD activity and polyunsaturated fatty acid composition of spermatozoa. MDA content in the spermatozoa of asthenozoospermic subjects was significantly higher than in normozoospermic males ( P < 0.05). Negative correlations were found between MDA content and seminal SOD activity and arachidonic acid content of spermatozoa from normozoospermic samples ( r = −0.5; P = 0.046, r = −0.9; P = 0.001 respectively). Seminal plasma GPX and SOD provide protection against lipid peroxidation of phospholipid and phospholipid-bound fatty acids in normozoospermic samples.

Association of classical semen parameters, sperm DNA fragmentation index, lipid peroxidation and antioxidant enzymatic activity of semen in ram-lambs

The objective was to determine relationships among classical semen characteristics, sperm chromatin structure assay (SCSA), lipid peroxidation and antioxidant enzymatic activity in ram-lamb semen. Fifty-seven ram-lambs were electroejaculated, and routine semen evaluation was conducted (as part of a breeding soundness evaluation). The percentage of sperm DNA fragmentation index (%DFI) and the percentage of sperm with abnormally high DNA stainability (HDS; immature spermatozoa) were determined by SCSA using the metachromatic properties of acridine orange. Semen was centrifuged at 800 × g for 15 min to separate spermatozoa and seminal plasma and the aliquots were stored at −70 °C until analyzed. Lipid peroxidation, superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels in seminal plasma and spermatozoa were measured by spectophotometric assays. The classical semen parameters were negatively related to lipid peroxidation and GPx activity in spermatozoa; motility and morphology were negatively related to %DFI ( P < 0.05). Based on Kruskal–Wallis pair-wise comparison of median values among breeding soundness outcome groups, %DFI was lower in the satisfactory group compared to other groups ( P < 0.05) and the lipid peroxidation and GPx activity in seminal plasma and spermatozoa were lower in satisfactory and questionable groups ( P < 0.05). However, the SOD was lower in the unsatisfactory group ( P < 0.05). In summary, classical semen parameters were negatively related to % DFI, lipid peroxidation and GPx activity in ram-lamb spermatozoa and seminal plasma. There were indications that SOD and GPx have crucial protective roles against the toxic effect of reactive oxygen species (ROS) in ram-lamb semen.

Activity, substrate detection and immunolocalization of glutathione peroxidase (GPx) in bovine reproductive organs and semen

The purpose of the current study was to further investigate the role of the antioxidant selenium-dependent enzyme glutathione peroxidase (GPx) in reproductive organs and semen from bulls. To this end a fast and convenient combined method for immune detection and substrate localization was adapted, which allows the assessment of both molecular weight and peroxidase activity of proteins on one and the same SDS-PAGE gel plate. After routine semen analysis of ejaculates, a spectrophotometrical assay of GPx activity in bovine semen was performed. For the immunological analyses performed, a rabbit polyclonal monospecific antibody against GPx was raised. Substrate detection and immunolocalization of GPx in lysates from bovine testis, epididymis, spermatozoa, and seminal plasma was performed. In order to determine the localization of GPx in spermatozoa, immunofluorescence analysis was performed. A positive correlation was established between GPx activity in semen and the number of motile spermatozoa. A negative correlation was observed between GPx activity and the number of immotile spermatozoa. The combined method for immunodetection and substrate localization was tested and proved reliable. Both tetramer and monomer forms of GPx were detected in lysates from testis, epididymis, and spermatozoa. We found no GPx activity in seminal plasma. Immunofluorescence shows the presence of GPx chiefly in the mitochondrial and in the acrosome regions of spermatozoa. GPx activity remained stable under the extreme experimental conditions.