• Journal of Life Science
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• v.33 no.7
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• pp.586-592
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• 2023

Oxidative stress is a critical factor affecting the quality and viability of sperm during boar semen storage. Oxidative stress is also a significant concern during the process of freezing semen. The process of semen storage involves exposing the sperm to various stressors, including temperature changes, cryoprotectants, and extended periods of incubation. In addition, oxidative stress can lead to the production of reactive oxygen species (ROS) within the sperm, resulting in oxidative damage to cellular components, such as lipids, proteins, and DNA. Striking a balance between ROS production and the antioxidant defense system is crucial for maintaining sperm viability and functionality during semen storage. Moreover, the prolonged storage of boar semen leads to an increase in ROS levels, which can impair sperm motility, membrane integrity, and DNA integrity. ROS-induced lipid peroxidation affects the fluidity and stability of sperm membranes, leading to decreased sperm motility. Moreover, oxidative damage to the DNA can result in DNA fragmentation, compromising the genetic integrity of the sperm. In conclusion, oxidative stress is a significant challenge in maintaining sperm quality during boar semen storage. Understanding the mechanisms underlying oxidative stress and their impacts on sperm function is crucial for developing effective strategies to minimize oxidative damage and improve sperm storage outcomes.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.201-206
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• 2001

This study was carried out to investigate the effects of spring (March~May) and summer (June~August) influencing semen characteristics, frozen-thawed sperm viability and serum testosterone concentration in Yorkshire boars. Results of this study were as follows: 1. There were no significant differences in the semen volume, pH and sperm concentration of sperm-poor fraction of Yorkshire boars between spring and summer. However, sperm concentrations of sperm-rich fractions in spring were higher than those in summer (P＜0.05). 2. Sperm motility and normal acrosome of raw semen in Yorkshire boars did not differ significantly between spring and summer, However, motility and normal acrosome of frozen-thawed sperm were higher in spring season than in summer season (P＜0.05). 3. Serum testosterone concentrations in Yorkshire boars were 4.04 ng/$m\ell$ in spring and 2.85 ng/$m\ell$ in summer. Serum testosterone concentrations in spring were higher than those in summer (P＜0.05). 4. In conclusion, when serum testosterone concentrations in Yorkshire boars were higher, frozen-thawed sperm viability was higher.

• Journal of Embryo Transfer
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• v.13 no.3
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• pp.277-289
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• 1998

To establish a system for sperm swim-up separation through sucrose layer, indiscreet sperm migration should sufficiently to block but movement of sperm shouldn't inhibit. Thus, the effects of sucrose levels in sucrose layer, incubation times and types of sucrose layer on sperm separation were examined. And the results obtained were as follows; 1. Layer of 10mM sucrose inhibited sperm swim-up migration through sucrose layer. 2. Incubation for 25 minutes without sucrose layer significantly increased sperm swim-up migration. However, incubation for 10 minutes to induce swim-up through sucrose layer significantly stimulated sperm migration and maintained sperm movement. 3. There was no significant difference between Type I and Type II in barrier effect of sucrose layer. However, sucrose layer of Type II with shorter distance of barrier was efficient for sampling. To elucidate a function of follicular fluid on sperm chemotaxis using in vitro system of sucrose layer of Type II and incubation for 10 minutes, the effects of dilution, heat treatment, and protein and lipid extracts of follicular fluid on sperm swim-up separation were examined. And the results obtained were as follows; 4. Follicular fluid stimulated sperm migration and movement, and significantly-attracted capacitated-sperm at 10% level. 5. Follicular fluid heated at 55$^{\circ}C$ for 30 minutes maintained the effect of follicular fluid stimulating sperm migration and movement. 6. Follicular protein stimulated sperm movement that was reduced by filtration of the protein. 7. Follicular lipid didn't significantly stimulate sperm migration and movement. 8. Both of follicular protein and lipid reduced the effect of follicular fluid stimulating sperm migration and movement. In conclusion, sucrose layer could be used for a barrier against indiscreet sperm migration by swim-up. And follicular fluid stimulated migration and movement of sperm and attracted capacitated-sperm through sucrose layer. Especially, heat-resistant protein of follicular fluid stimulated sperm migration.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.413-421
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• 1987

The objective of this study was to evaluate the possibility of sex preselection by gradients methods using bovine serum albumin in rabbits. Artificial insemination with separated sperm was performed, after highly motile sperm were separated by different methods using 6%, 10% and 20% bovine serum albumin. Various characteristics of separated sperm, and the conception rate and secondary sex ratio at artificial insemination with sperm separated by different methods were compared. The results obtained were as follows. 1. The conception rate of sperm separated by bovine serum albumin gradients was higher than th at of control sperm. But secondary sex ratio was not altered by this methods. 2. The sperm separated by bovine serum albumin gradients showed significantly high value in motility, percent of normal sperm and progressive motility as compared with control sperm and revealed the highest sperm recovery when separated with 6% bovine serum albumin. 3. The sperm motility, percent of normal sperm and progressive motility of the highly motile sperm frozen after being separated from raw semen with bovine serum albumin, showed significantly high value than those of control sperm.

• 대한생식의학회:학술대회논문집
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• 1995.12a
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• pp.53.2-54
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• 1995

• Clinical and Experimental Reproductive Medicine
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• v.34 no.3
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• pp.159-166
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• 2007

Objective: To investigate whether semen parameters in infertile couples who undergone intrauterine insemination (IUI) change in the subsequent IUI cycle and the subsequent in vitro fertilization (IVF) cycle. Methods: Fifty-three infertile couples who had failed to become pregnant after the first IUI cycle with computer-assisted semen analysis (CASA) were included. After the first IUI, thirty-eight couples underwent the second IUI (Group 1), and fifteen underwent IVF-ET procedure (Group 2). All semen parameters including semen volume, concentration, motility and total motile sperm count were analyzed in the second IUI or IVF-ET procedure for comparison with the result of first IUI. Results: There were no significant differences in husband age, interval between the first and second procedure and cause of infertility. In Group 1, only sperm motility at the time of the latter IUI was significantly decreased when compared to the former IUI irrespective of the first semen parameters. In Group 2, sperm concentration, motility and total motile sperm count at the time of subsequent IVF were lower than the former IUI. By sub-analyses of Group 2, in the group of optimal semen parameter at IUI cycle, sperm concentration and total motile sperm count at the time of subsequent IVF were lower than the former IUI, while in the group of suboptimal semen parameter at IUI cycle, only sperm motility at the time of subsequent IVF were lower than the former IUI. Conclusion: The semen parameters in couples converted to IVF cycle were more adversely affected than those remained in IUI cycle. Further study on psychological stress should be necessary to explain the reason.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.238-241
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• 1999

Experiments were performed to find out the physico-chemical properties of milt and the sperm motilities in various conditions using the grey mullet, Mugil cephalus. The average concentration of sperm in the milt was $1,11 \pm0.36\times10^{10}/ml$. Spermatocrit was 96.7$\pm$2.6. pH and osmolality of seminal fluid were 7.8$\pm$0.1, 370$\pm$6 mOsm/kg, respectively, Total protein concentration of sperm was higher than that of seminal fluid, but total lipid concentration of seminal fluid was higher than that of sperm. The sperm motility was high in the diluent of milt : artificial seawater (1:10, by volume) and in 822 mOsm/kg and 983 mOsm/kg similar to seawater osmolality, but it decreased after 20 minutes. But activity of sperm was highly maintained in 482 mOsm/kg which was a little higher than osmolality of seminal fluid, and was high in pH 7$\~$9.

• Journal of Marine Life Science
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• v.2 no.1
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• pp.1-6
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• 2017

The purpose of this research is to develop the simple freezing method for sperm cryopreservation in the Sevenband grouper and Kelp grouper. The motility and survival rate were checked to investigate the effects of diluent and cryoprotectant on sperm cryopreservation.In cryopreservation experiments, 300 mM glucose and 15% dimethyl sulfoxide (DMSO) were used as a diluent and a cryoprotectant, respectively. As a results of cryopreservation, the motility rate of Sevenband grouper was found to be more than 90%, and that of Kelp grouper was found to be more that 60% in sperm 5 months after cryopreservation.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.729-736
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• 2007

The objective of this study was to investigate the anti-oxidative effects of pyruvate, taurine and melatonin on sperm characteristics(motility, membrane integrity) and lipid peroxidation(LPO) for in vitro storage of boar semen. Semen was treated with various antioxidants such as pyruvate(1mM), taurine(50mM) and melatonin(100nM) with or without 100uM H2O2. Antioxidant treatments were significantly increased the sperm motility when compare to control group in all incubation periods(P≤0.05). Hypoosmotic swelling test(HOST), membrane integrity was similar to the result of motility. In lipid peroxidation measurement by TBA reactions of spermatozoal plasma membrane, malondialdehyde(MDA) level in control and antioxidant treatments were lower than those of antioxidant plus H2O2 or H2O2 treatment for 3 to 6 h incubation period. Relationships of evaluation methods for sperm viability were investigated by motility, membrane integrity and lipid peroxidation. Among evaluation methods, LPO vs motility and membrane integrity vs LPO were negatively correlated(－0.23~－0.92 and －0.68~－0.85), but membrane integrity vs motility was positively correlated (0.53~0.94) in all treatments. These experiments indicate that supplementation of antioxidant to the semen extender can increase the sperm motility and membrane integrity and decrease the lipid peroxidation of spermatozoal plasma membrane. The HOST might be utilized to evaluate the sperm quality instead of lipid peroxidation or motility.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.486-492
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• 2007

Seminal plasma(SP) is usually removed from semen that is to be cryopreserved. However, some reports indicate that SP has beneficial effects on spermatozoa during chilling and freezing. The purpose of this study was to determine the effect of SP on sperm survival by adding SP to the extender before cooling and freezing canine spermatozoa. In replicate experiments, ejaculates obtained from four healthy dogs(1-4 years old) of various breeds were pooled, centrifuged at $300{\times}g$ for 10 min at $25^{\circ}C$, and the supernatant of seminal plasma was decanted. Spermatozoa were suspended in egg yolk-Tris(EYT) buffer. The study comprised two experiments: [Exp 1] Sperm were suspended in EYT extender containing either 0, 20, 40, 80 or 100% SP and were slowly cooled to $4^{\circ}C$ for 2h or held at $25^{\circ}C$ as controls. Sperm concentration was adjusted to $2{\times}10^8/ml$. [Exp II] Sperm samples, each of which contained $1{\times}10^8/ml$, were assigned to nine groups to be frozen. In the first four groups, sperm in EYT containing either 20, 40, 80 or 100% SP were cooled to $4^{\circ}C$, then diluted to contain final concentrations of EYT+0.6M glycerol and then were frozen. The final concentrations of SP were 10, 20, 40 or 50%. In the other four groups, sperm in EYT alone were first cooled slowly to $4^{\circ}C$, then diluted to contain final concentrations of EYT+0.6M glycerol plus 10, 20, 40 or 50% SP and then were frozen. Spermatozoa, which chilled in EYT alone and diluted to contain final concentrations of EYT+0.6M glycerol without seminal plasma, and then frozen, was regarded as control. Spermatozoa were frozen at $25^{\circ}C/min$ of cooling rate in plastic straws that were suspended above liquid nitrogen and thawed in water at $38^{\circ}C$ for 1 min. Sperm survival was assayed by determining progressive motility and integrity of plasma and acrosome membranes. Progressive motility was determined by microscopic examination at $200{\times}$ magnification. Membrane integrity was assessed by use of a double fluorescent dye, and acrosome integrity by staining sperm with Pisum sativum agglutinin. The results of the first experiment showed that adding SP did not improve motility of spermatozoa compared to those incubated without SP regardless of temperature. The results of the second experiment showed that spermatozoa suspended in EYT+0.6M glycerol containing SP exhibited the higher progressive motility before being frozen(P<0.05). However, frozen-thawed spermatozoa that had suspended in EYT+0.6M glycerol containing SP showed the similar or lower viability(P<0.05). In summary, although seminal plasma did not affect spermatozoa that were chilled in EYT without cryoprotectant(CPA), addition of seminal plasma to EYT containing CPA did significantly improved progressive motility of canine spermatozoa that were chilled.