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de Oliveira RA, Wolf CA, de Oliveira Viu MA, Gambarini ML. Addition of Glutathione to an Extender for Frozen Equine Semen. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2013.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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52
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Martorana K, Klooster K, Meyers S. Suprazero cooling rate, rather than freezing rate, determines post thaw quality of rhesus macaque sperm. Theriogenology 2013; 81:381-8. [PMID: 24239181 DOI: 10.1016/j.theriogenology.2013.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/02/2013] [Accepted: 10/04/2013] [Indexed: 12/16/2022]
Abstract
Sperm become most sensitive to cold shock when cooled from 37 °C to 5 °C at rates that are too fast or too slow; cold shock increases the susceptibility to oxidative damage owing to its influence on reactive oxygen species (ROS) production, which are significant stress factors generated during cooling and low temperature storage. In addition, ROS may be a main cause of decreased motility and fertility upon warming. They have been shown to change cellular function through the disruption of the sperm plasma membrane and through damage to proteins and DNA. The objective of this study was to determine which cryopreservation rates result in the lowest degree of oxidative damage and greatest sperm quality. In the rhesus model, it has not been determined whether suprazero cooling or subzero freezing rates causes a significant amount of ROS damage to sperm. Semen samples were collected from male rhesus macaques, washed, and resuspended in TEST-yolk cryopreservation buffer to 100 × 10(6) sperm/mL. Sperm were frozen in 0.5-mL straws at four different combinations of suprazero and subzero rates. Three different suprazero rates were used between 22 °C and 0 °C: 0.5 °C/min (slow), 45 °C/min (medium), and 93 °C/min (fast). These suprazero rates were used in combination with two different subzero rates for temperatures 0 °C to -110 °C: 42 °C/min (medium) and 87 °C/min (fast). The different freezing groups were as follows: slow-med (SM), slow-fast (SF), med-med (MM), and fast-fast (FF). Flow cytometry was used to detect lipid peroxidation (LPO), a result of ROS generation. Motility was evaluated using a computer assisted sperm motion analyzer. The MM and FF treated sperm had less viable (P < 0.0001) and motile sperm (P < 0.001) than the SM, SF, or fresh sperm. Sperm exposed to MM and FF treatments demonstrated significantly higher oxidative damage than SM, SF, or fresh sperm (P < 0.05). The SM- and SF-treated sperm showed decreased motility, membrane integrity, and LPO compared with fresh semen (P < 0.001). Slow cooling from room temperature promotes higher membrane integrity and motility post thaw, compared with medium or fast cooling rates. Cells exposed to similar cooling rates with differing freezing rates were not different in motility and membrane integrity, whereas comparison of cells exposed to differing cooling rates with similar freezing rates indicated significant differences in motility, membrane integrity, and LPO. These data suggest that sperm quality seems to be more sensitive to the cooling, rather than freezing rate and highlight the role of the suprazero cooling rate in post thaw sperm quality.
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Affiliation(s)
- Kelly Martorana
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Katie Klooster
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Stuart Meyers
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA.
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Partyka A, Niżański W, Bajzert J, Łukaszewicz E, Ochota M. The effect of cysteine and superoxide dismutase on the quality of post-thawed chicken sperm. Cryobiology 2013; 67:132-6. [DOI: 10.1016/j.cryobiol.2013.06.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 05/02/2013] [Accepted: 06/04/2013] [Indexed: 11/29/2022]
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54
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Effects of α-tocopherol and Ascorbic Acid on Equine Semen Quality after Cryopreservation. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2012.12.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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55
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Abstract
The generation of reactive oxygen species associated with cryopreservation could be responsible for mammalian sperm damage and the limitable value of stored semen in artificial insemination. The aim of this study was to assess several antioxidant agents supplemented in a commercial freezing extender (Gent B®) in order to improve post-thaw rabbit sperm quality. Ejaculates of 26 New Zealand White rabbit bucks were collected, evaluated and frozen using a conventional protocol. Antioxidant agents were tested at different concentrations: bovine serum albumin (BSA; 5, 30 or 60 mg/ml), retinol (RO; 50, 100 or 200 μM) and retinyl (RI; 0.282 or 2.82 μg/ml). Per cent viability, morphological abnormalities and intact acrosomes were determined using eosin-nigrosin staining. Motility and progressivity were analyzed by computer-assisted sperm analysis (CASA). In general, all sperm quality parameters were negatively affected by the cryopreservation process, the largest effect seen was for total motility. The addition of antioxidant agents did not improve thaw sperm quality. Furthermore, for RI groups a significant decrease in sperm quality parameters was recorded. In conclusion, rabbit sperm quality is negatively affected by the cryopreservation process. To our knowledge this report is the first using these antioxidants to supplement rabbit freezing extender. BSA and RO at concentrations used in the study did not improve sperm quality parameters after thawing, whereas RI supplementation appeared to be toxic. More studies are required to find the appropriate antioxidants necessary and their most effective concentrations to improve rabbit post-thaw sperm quality.
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56
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Barros L, Silva S, Almeida F, Silva E, Carneiro G, Guerra M. Efeito da adição de glutationa peroxidase e cisteína ao diluidor de congelação do sêmen equino. ARQ BRAS MED VET ZOO 2013. [DOI: 10.1590/s0102-09352013000200019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Foram utilizados ejaculados (n=25) de garanhões para avaliar o efeito de glutationa peroxidase (GPx) e cisteína na viabilidade de espermatozoides congelados. O sêmen foi diluído em Botu Crio, com antioxidantes, e foram formados os grupos: G1, Controle; G2, 1U GPx ; G3, 5U GPx; G4, 0,5mM cisteína; G5, 1mM cisteína. Depois foi envasado em palhetas (0,5mL) e congelado. Após descongelação, 37°C por 30 segundos, alíquotas foram analisadas quanto à integridade de membrana plasmática (IMP) e acrossoma (IAc), potencial de membrana mitocondrial (PMM) e cinética, nos tempos zero (T0) e 60 minutos (T60). GPx 5U e cisteína 0,5mM determinaram maior (P<0,05) IAc em T0 do que em T60. Cisteína 1mM resultou em maior (P<0,05) IAc em T60 do que GPx 1 e 5U e cisteína 0,5mM. O PMM de um garanhão no T60 foi mais alto (P<0,05) do que o de dois garanhões. VCL e VAP foram maiores (P<0,05) no T0 do que no T60 do grupo controle, e um garanhão apresentou, em geral, valores cinéticos mais altos (P<0,05) do que os demais. Conclui-se que a adição de glutationa peroxidase, nas concentrações de 1U e 5U, e de cisteína, nas concentrações de 0,5mM e 1mM, não interferem na integridade de espermatozoides criopreservados de equinos, mas preservam os parâmetros cinéticos de VCL e VAP após 60 minutos de incubação. Ressalta-se, ainda, que o garanhão tem uma forte influência nas características espermáticas pós-congelação.
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Affiliation(s)
| | - S.V. Silva
- Universidade Federal Rural de Pernambuco
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57
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Nenkova G, Alexandrova A. A review: Oxidative stress and its role in reproduction. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/abb.2013.41006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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58
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Peña FJ, Ferrusola CO, Tapia JA, Aparicio IM. How Stallion Sperm Age In Vitro? Scenario for Preservation Technologies. J Equine Vet Sci 2012. [DOI: 10.1016/j.jevs.2012.05.074] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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59
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Díez C, Muñoz M, Caamaño JN, Gómez E. Cryopreservation of the Bovine Oocyte: Current Status and Perspectives. Reprod Domest Anim 2012; 47 Suppl 3:76-83. [DOI: 10.1111/j.1439-0531.2012.02029.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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60
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McCarthy MJ, Meyers SA. Antioxidant treatment in the absence of exogenous lipids and proteins protects rhesus macaque sperm from cryopreservation-induced cell membrane damage. Theriogenology 2011; 76:168-76. [PMID: 21458048 DOI: 10.1016/j.theriogenology.2011.01.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 01/26/2011] [Accepted: 01/27/2011] [Indexed: 12/09/2022]
Abstract
Osmotic stress caused oxidative stress in rhesus macaque sperm, which was alleviated by antioxidant supplementation. The objective of the present study was to demonstrate that cryopreservation of rhesus macaque sperm also induces reactive oxygen species (ROS) production, and to determine whether ROS have an important role in cryopreservation-induced membrane. Additionally, we evaluated the antioxidant capacity of TEST (N-Tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid-Tris) buffer (with 20% egg yolk and 13% skim milk) and supplementation with antioxidants, superoxide dismutase (SOD), catalase (CAT), and α-tocopherol. There was a substantial level of ROS production in both the presence (15% increase in superoxide, P < 0.01; 14% increase in hydrogen peroxide, P < 0.01) and absence of egg yolk (EY) and skim milk (SM; 33% increase in superoxide, P < 0.001; 48% increase in hydrogen peroxide, P < 0.001). Superoxide dismutase provided little membrane protection against ROS, but increased postthaw total and progressive motility by 10% (P < 0.01) and 15% (P < 0.05), respectively. Supplementation with CAT and α-tocopherol in the presence of EY and SM decreased H(2)O(2) by 55% (P < 0.01) and 49% (P < 0.001), whereas supplementation with CAT and α-tocopherol in the absence of EY and SM reduced the level of lipid peroxidation by 61% (P < 0.05) and 28% (P < 0.01). In conclusion, this is apparently the first report that cryopreservation of rhesus macaque sperm induced a significant increase in ROS and that antioxidant supplementation (N-Tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid-Tris) can significantly decrease the extent of ROS-induced membrane damage.
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Affiliation(s)
- Megan J McCarthy
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA
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61
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Wnuk M, Lewinska A, Oklejewicz B, Bartosz G, Tischner M, Bugno-Poniewierska M. Redox status of equine seminal plasma reflects the pattern and magnitude of DNA damage in sperm cells. Theriogenology 2010; 74:1677-84. [DOI: 10.1016/j.theriogenology.2010.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 07/03/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
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62
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Thuwanut P, Chatdarong K, Johannisson A, Bergqvist AS, Söderquist L, Axnér E. Cryopreservation of epididymal cat spermatozoa: effects of in vitro antioxidative enzymes supplementation and lipid peroxidation induction. Theriogenology 2010; 73:1076-87. [DOI: 10.1016/j.theriogenology.2010.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 12/21/2009] [Accepted: 01/09/2010] [Indexed: 10/19/2022]
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63
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The protective effects of alpha-ketoacids against oxidative stress on rat spermatozoa in vitro. Asian J Androl 2009; 12:247-56. [PMID: 20010848 DOI: 10.1038/aja.2009.78] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The aim of this study was to determine the effects of antioxidants, including alpha-ketoacids (alpha-ketoglutarate and pyruvate), lactate and glutamate/malate combination, against oxidative stress on rat spermatozoa. Our results showed that H(2)O(2) (250 micromol L(-1))-induced damages, such as impaired motility, adenosine triphosphate (ATP) depletion, inhibition of sperm protein phosphorylation, reduced acrosome reaction and decreased viability, could be significantly prevented by incubation of the spermatozoa with alpha-ketoglutarate (4 mmol L(-1)) or pyruvate (4 mmol L(-1)). Without exogenous H(2)O(2) in the medium, the addition of pyruvate (4 mmol L(-1)) significantly increased the superoxide anion (O(2)(-).) level in sperm suspension (P < or = 0.01), whereas the addition of alpha-ketoglutarate (4 mmol L(-1)) and lactate (4 mmol L(-1)) significantly enhanced tyrosine-phosphorylated proteins with the size of 95 kDa (P < or = 0.04). At the same time, alpha-ketoglutarate, pyruvate, lactate, glutamate and malate supplemented in media can be used as important energy sources and supply ATP for sperm motility. In conclusion, the present results show that alpha-ketoacids could be effective antioxidants for protecting rat spermatozoa from H(2)O(2) attack and could be effective components to improve the antioxidant capacity of Biggers, Whitten and Whittingham media.
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64
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McCarthy MJ, Baumber J, Kass PH, Meyers SA. Osmotic stress induces oxidative cell damage to rhesus macaque spermatozoa. Biol Reprod 2009; 82:644-51. [PMID: 19846599 DOI: 10.1095/biolreprod.109.080507] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Cryopreservation introduces extreme temperature and osmolality changes that impart lethal and sublethal effects on spermatozoa survival. Additionally, evidence indicates that the osmotic stress induced by cryopreservation causes oxidative stress to spermatozoa as well. Our objective was to determine the effect of reactive oxygen species (ROS) on rhesus macaque (Macaca mulatta) sperm function and to determine whether osmotic stress elicits the production of ROS. In the first experiment, the xanthine-xanthine oxidase (X-XO) system was used to generate the ROS superoxide anion (O(2)(-.)) and hydrogen peroxide (H(2)O(2)) in the presence or absence of the ROS scavengers superoxide dismutase and catalase, respectively. In the second experiment, osmotic stress was introduced by incubation of spermatozoa in a series of anisosmotic media ranging from 100 to 1000 mOsmol/kg in the presence or absence of the antioxidant alpha-tocopherol. Treatment with the X-XO system resulted in a significant increase in the generation of O(2)(-.) and H(2)O(2) that was detectable using flow cytometry. The ROS generated by the X-XO system was dose dependent, and as the concentration of ROS increased, motility decreased and lipid peroxidation increased while no affect was observed on viability. Incubation of spermatozoa in anisosmotic media also resulted in an increase in O(2)(-.) generation and lipid peroxidation that was significantly decreased in the presence of the powerful antioxidant alpha-tocopherol. These results clearly indicate that osmotic stress causes oxidative stress in rhesus macaque spermatozoa, which strongly supports the hypothesis that cryopreservation-induced osmotic stress may lead to oxidative cell damage.
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Affiliation(s)
- Megan J McCarthy
- Departments of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA
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65
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Fernández-Santos MR, Domínguez-Rebolledo AE, Esteso MC, Garde JJ, Martínez-Pastor F. Catalase supplementation on thawed bull spermatozoa abolishes the detrimental effect of oxidative stress on motility and DNA integrity. ACTA ACUST UNITED AC 2009; 32:353-9. [DOI: 10.1111/j.1365-2605.2008.00871.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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66
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Oxidative stress, osmotic stress and apoptosis: Impacts on sperm function and preservation in the horse. Anim Reprod Sci 2008; 107:257-67. [DOI: 10.1016/j.anireprosci.2008.04.014] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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67
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Chi H, Kim J, Ryu C, Lee J, Park J, Chung D, Choi S, Kim M, Chun E, Roh S. Protective effect of antioxidant supplementation in sperm-preparation medium against oxidative stress in human spermatozoa. Hum Reprod 2008; 23:1023-8. [DOI: 10.1093/humrep/den060] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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68
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Baumgartner A, Cemeli E, Anderson D. The comet assay in male reproductive toxicology. Cell Biol Toxicol 2007; 25:81-98. [PMID: 17972149 DOI: 10.1007/s10565-007-9041-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 10/03/2007] [Indexed: 01/23/2023]
Abstract
Due to our lifestyle and the environment we live in, we are constantly confronted with genotoxic or potentially genotoxic compounds. These toxins can cause DNA damage to our cells, leading to an increase in mutations. Sometimes such mutations could give rise to cancer in somatic cells. However, when germ cells are affected, then the damage could also have an effect on the next and successive generations. A rapid, sensitive and reliable method to detect DNA damage and assess the integrity of the genome within single cells is that of the comet or single-cell gel electrophoresis assay. The present communication gives an overview of the use of the comet assay utilising sperm or testicular cells in reproductive toxicology. This includes consideration of damage assessed by protocol modification, cryopreservation vs the use of fresh sperm, viability and statistics. It further focuses on in vivo and in vitro comet assay studies with sperm and a comparison of this assay with other assays measuring germ cell genotoxicity. As most of the de novo structural aberrations occur in sperm and spermatogenesis is functional from puberty to old age, whereas female germ cells are more complicated to obtain, the examination of male germ cells seems to be an easier and logical choice for research and testing in reproductive toxicology. In addition, the importance of such an assay for the paternal impact of genetic damage in offspring is undisputed. As there is a growing interest in the evaluation of genotoxins in male germ cells, the comet assay allows in vitro and in vivo assessments of various environmental and lifestyle genotoxins to be reliably determined.
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Affiliation(s)
- A Baumgartner
- Division of Biomedical Sciences, University of Bradford, Richmond Road, Bradford, West Yorkshire BD7 1DP, UK
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69
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Dynamics of sperm DNA fragmentation in domestic animals II. The stallion. Theriogenology 2007; 68:1240-50. [PMID: 17919715 DOI: 10.1016/j.theriogenology.2007.08.029] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 08/17/2007] [Accepted: 08/21/2007] [Indexed: 11/23/2022]
Abstract
The mixed success of equine artificial insemination programs using chilled and frozen-thawed semen is most likely associated with the variable response of the sperm cell to the preservation process and the fact that stallions are not selected on the basis of reproductive performance. We propose that the traditional indicators of sperm viability do not fully account for male factor infertility in the stallion and that knowledge of sperm DNA damage in the original semen sample and during semen processing may provide a more informed explanation of an individual stallion's reproductive potential. This study reports on the validation of a sperm DNA fragmentation test based on the sperm chromatin dispersion test (SCD) for stallion spermatozoa and on its application to semen that was chilled (4 degrees C; n=10) or frozen-thawed (n=13). Semen samples were collected by artificial vagina and the proportion of sperm with fragmented DNA determined. Seminal plasma was then removed by centrifugation and the sperm pellet re-suspended in commercial extenders prior to being chilled or cryopreserved using standard industry protocols. Chilled semen was cooled slowly to 4 degrees C and stored for 1h before commencing the analysis; cryopreserved semen was thawed and immediately analyzed. Following chilling or cryopreservation, the semen samples were incubated at 37 degrees C and analyzed for SCD after 0, 4, 6, 24 and 48 h storage. The results of this investigation revealed that there was no significant difference in the sperm DNA fragmentation index (sDFI) of sperm evaluated initially after collection compared to those tested immediately after chilling or cryopreservation. However, within 1h of incubation at 37 degrees C, both chilled and frozen-thawed spermatozoa showed a significant increase in the proportion of sDFI; after 6h the sDFI had increased to over 50% and by 48 h, almost 100% of the sperm showed DNA damage. While the sDFI of individual stallions at equivalent times of incubation was variable, an analysis of the rate of change of sDFI revealed no difference between stallions or the way in which the semen was preserved. In terms of sperm DNA fragmentation dynamics, the highest intensity of sperm DNA damage occurred in the first 6h of incubation. We suggest that the SCD test can be used as a routine assessment tool for the development and refinement of preservation protocols designed to reduce stallion sperm DNA damage.
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70
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Ledda S, Bogliolo L, Succu S, Ariu F, Bebbere D, Leoni GG, Naitana S. Oocyte cryopreservation: oocyte assessment and strategies for improving survival. Reprod Fertil Dev 2007; 19:13-23. [PMID: 17389131 DOI: 10.1071/rd06126] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Despite significant progress in cryopreservation of mammalian oocytes and embryos, many of the molecular and biochemical events that underlie this technology are poorly understood. In recent years, researchers have focused on obtaining viable oocytes that are developmentally competent. Even under the most favourable conditions, experimental approaches have achieved only limited success compared with fresh oocytes used in routine in vitro embryo production. Chilling injuries and toxic effects of the cryoprotectants are the major adverse consequences following cryoprocedures. To overcome these problems, different strategies have been developed for improving cryopreservation results. These strategies include reducing container volumes, increasing the thermal gradient, changing the cell surface/volume ratio, enhancing cryotolerance by supplementation with various additives or modifying the lipid composition of the oocyte membrane. In order to develop new strategies for reducing the various forms of stress associated with oocyte cryopreservation, it is fundamental to gain a better understanding of the major changes responsible for poor post-thaw survival. With this knowledge, we hope that oocyte cryostorage will become a fully reliable reproductive technique in the near future.
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Affiliation(s)
- Sergio Ledda
- Department of Animal Biology, Veterinary Faculty, University of Sassari, 07100 Sassari, Italy.
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71
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Thomas AD, Meyers SA, Ball BA. Capacitation-like changes in equine spermatozoa following cryopreservation. Theriogenology 2006; 65:1531-50. [PMID: 16225914 DOI: 10.1016/j.theriogenology.2005.08.022] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Accepted: 08/25/2005] [Indexed: 11/29/2022]
Abstract
The primary objective of this study was to assess plasma membrane characteristics and activation of signal transduction pathways in equine spermatozoa during both in vitro capacitation and cryopreservation. Significant plasma membrane restructuring, as assessed by measurement of plasma membrane lipid disorder and phospholipid scrambling, was not observed until after cryopreservation and subsequent thawing (P < 0.05). Although in vitro capacitated cells also displayed increased plasma membrane lipid disorder and phospholipid scrambling (P < 0.05), it appeared that regulation of these events in in vitro capacitated versus cryopreserved equine spermatozoa was not identical. Addition of 5 microM staurosporine to the capacitation media reduced plasma membrane phospholipid scrambling (P < 0.05), but supplementation to the freezing extender prior to cryopreservation did not. Furthermore, progesterone was able to induce a greater degree of acrosomal exocytosis in in vitro capacitated versus frozen/thawed spermatozoa. Expression of phospholipid scramblase, a protein thought to be important in plasma membrane phospholipid scrambling, did not differ between treatments. Comparison of protein tyrosine phosphorylation patterns between in vitro capacitated and cryopreserved cells demonstrated a divergence in signal transduction. Cellular signaling in in vitro capacitated equine spermatozoa appeared to be in part dependent on activation of the cAMP/PKA pathway, whereas signaling in cryopreserved cells seemed to proceed predominantly through alternative pathways. Taken together, these data support the idea that capacitation and "cryocapacitation" are not equivalent processes.
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Affiliation(s)
- A D Thomas
- Department of Population, Health, and Reproduction, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
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