Sperm survival kinetics in different types of bull semen: progressive motility, plasma membrane integrity, acrosomal status and reactive oxygen species generation
Mushtaq Ahmad A B , Nasim Ahmad B , Amjad Riaz B and Muhammad Anzar A C D
+ Author Affiliations
- Author Affiliations
A Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7S 1K9, Canada.
B Department of Theriogenology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan.
C Agriculture and Agri-Food Canada, Saskatoon Research Center, Saskatoon, SK S7N 0X2, Canada.
D Corresponding author. Emails: muhammad.anzar@agr.gc.ca; muhammad.anzar@usask.ca
Reproduction, Fertility and Development 27(5) 784-793 https://doi.org/10.1071/RD13400
Submitted: 4 June 2013 Accepted: 19 January 2014 Published: 28 February 2014
Abstract
This study was designed to compare the kinetics of sperm survival in different types of bull semen. Fresh ejaculates from four bulls were pooled, diluted in Tris-citric acid-egg yolk-glycerol extender, cooled to 4°C, frozen in LN2 and thawed at 37°C. Fresh, diluted, cooled and frozen–thawed semen were incubated at 37°C, and evaluated at 0, 2, 4, 6, 12 and 24 h after the beginning of incubation. In Experiment 1, progressive sperm motility, normal acrosomes and plasma membrane integrity and asymmetry were determined. In Experiment 2, generation of superoxide anion (O2•) along with plasma membrane permeability and generation of hydrogen peroxide (H2O2) along with plasma membrane integrity were assessed. In Experiment 1, frozen–thawed semen had shorter survival times for progressive sperm motility, and spermatozoa with intact plasma membranes and acrosomes (IPM-IACR) as compared with other types of semen (P < 0.05). Fresh spermatozoa underwent a necrotic pathway, diluted and cooled spermatozoa underwent an apoptosis-like pathway and frozen–thawed spermatozoa underwent both necrotic and apoptosis-like pathways. In Experiment 2, spermatozoa in all four types of semen exhibited O2•– generation and increased plasma membrane permeability, and became necrotic without H2O2 generation during incubation (P < 0.05). In conclusion, frozen–thawed semen had shorter sperm longevity, which has important implications relating to the timing of artificial insemination. Different types of semen followed different death pathways. During incubation, spermatozoa in all types of semen generated O2•–, which increased the permeability and compromised the integrity of the plasma membrane.
Additional keywords: cryopreservation, hydrogen peroxide, membrane asymmetry, membrane permeability, superoxide anion.
References
Aalseth, E. P., and Saacke, R. G. (1987). Alteration of the anterior acrosome of motile bovine spermatozoa by fructose and hydrogen ion concentration. J. Reprod. Fertil. 81, 625–634.| Alteration of the anterior acrosome of motile bovine spermatozoa by fructose and hydrogen ion concentration.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1cXhvFOlsQ%3D%3D&md5=d8dac161f649906496d6d53789fde16cCAS | 3430478PubMed |
Aitken, R. J., and Koppers, A. J. (2011). Apoptosis and DNA damage in human spermatozoa. Asian J. Androl. 13, 36–42.
| Apoptosis and DNA damage in human spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtlejtQ%3D%3D&md5=3a6b5010a38894f4a57bc8bd7a2b5224CAS | 20802502PubMed |
Alvarez, J. G., and Storey, B. T. (1992). Evidence for increased lipid peroxidative damage and loss of superoxide dismutase activity as a mode of sub-lethal cryodamage to human sperm during cryopreservation. J. Androl. 13, 232–241.
| 1:CAS:528:DyaK38Xlt1yqs7o%3D&md5=7b9e2dd159130e08bb254ee059135fcdCAS | 1601742PubMed |
Anand-Ivell, R., and Ivell, R. (2011). The special systems biology of the sperm. Biochem. J. 436, e3–e5.
| The special systems biology of the sperm.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXntV2gsb0%3D&md5=b68a65ce3b3befbc0d24f1e42b9f447fCAS | 21615332PubMed |
Anzar, M., He, L., Buhr, M. M., Kroetsch, T. G., and Pauls, K. P. (2002). Sperm apoptosis in fresh and cryopreserved bull semen detected by flow cytometry and its relationship with fertility. Biol. Reprod. 66, 354–360.
| Sperm apoptosis in fresh and cryopreserved bull semen detected by flow cytometry and its relationship with fertility.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XotVSlsQ%3D%3D&md5=2864ec5fc2189607f37f02d74b180069CAS | 11804948PubMed |
Anzar, M., Rasul, Z., Ahmed, T. A., and Ahmad, N. (2010). Response of buffalo spermatozoa to low temperatures during cryopreservation. Reprod. Fertil. Dev. 22, 871–880.
| Response of buffalo spermatozoa to low temperatures during cryopreservation.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3czitFGhtw%3D%3D&md5=b8a8e2f9e72b5ca6d570ea71b48c789cCAS | 20450839PubMed |
Anzar, M., Kroetsch, T., and Boswall, L. (2011). Cryopreservation of bull semen shipped overnight and its effect on post-thaw sperm motility, plasma membrane integrity, mitochondrial membrane potential and normal acrosomes. Anim. Reprod. Sci. 126, 23–31.
| Cryopreservation of bull semen shipped overnight and its effect on post-thaw sperm motility, plasma membrane integrity, mitochondrial membrane potential and normal acrosomes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXosVCrsro%3D&md5=22f29a3d20846ff9d758c27a955661a0CAS | 21621352PubMed |
Bag, S., Joshi, A., Naqvi, S. M., and Mittal, J. P. (2004). Effect of post-thaw incubation on sperm kinematics and acrosomal integrity of ram spermatozoa cryopreserved in medium-sized French straws. Theriogenology 62, 415–424.
| Effect of post-thaw incubation on sperm kinematics and acrosomal integrity of ram spermatozoa cryopreserved in medium-sized French straws.Crossref | GoogleScholarGoogle Scholar | 15225998PubMed |
Bailey, J. L., Bilodeau, J. F., and Cormier, N. (2000). Semen cryopreservation in domestic animals: a damaging and capacitating phenomenon. J. Androl. 21, 1–7.
| 1:STN:280:DC%2BD3c7jtl2ktg%3D%3D&md5=3f82f60e72bd0fbdba61e5da41bee564CAS | 10670514PubMed |
Baker, M. A., and Aitken, R. J. (2005). Reactive oxygen species in spermatozoa: methods for monitoring and significance for the origins of genetic disease and infertility. Reprod. Biol. Endocrinol. 3, 67.
| Reactive oxygen species in spermatozoa: methods for monitoring and significance for the origins of genetic disease and infertility.Crossref | GoogleScholarGoogle Scholar | 16313680PubMed |
Barth, A. D. (2007) Evaluation of potential breeding soundness of the Bull. In ‘Current Therapy in Large Animal Theriogenology 2’. (Eds R.S. Youngquist and R.W. Threlfall.) pp. 228–240. (Saunders Elsevier: Philadelphia.)
Batista, M., Nino, T., Santana, M., Alamo, D., Castro, N., Reyes, R., Gonzalez, F., Cabrera, F., and Gracia, A. (2011). Influence of the preservation temperature (37, 20, 4, –196°C) and the mixing of semen over sperm quality of majorera bucks. Reprod. Domest. Anim. 46, 281–288.
| Influence of the preservation temperature (37, 20, 4, –196°C) and the mixing of semen over sperm quality of majorera bucks.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3M3lvV2nsg%3D%3D&md5=bcdb055838a2ab216f5298c821cd5abfCAS | 20565698PubMed |
Bedford, S. J., Gowdy, H. L., and Hinrichs, K. (1999). Comparison of the longevity of motility of stallion spermatozoa incubated at 38°C in different capacitating media and containers. Theriogenology 51, 637–646.
| Comparison of the longevity of motility of stallion spermatozoa incubated at 38°C in different capacitating media and containers.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3c7ptFeqsA%3D%3D&md5=6fb26bddf297dd9e84dcacb11741031eCAS | 10729048PubMed |
Bilodeau, J. F., Chatterjee, S., Sirard, M. A., and Gagnon, C. (2000). Levels of antioxidant defences are decreased in bovine spermatozoa after a cycle of freezing and thawing. Mol. Reprod. Dev. 55, 282–288.
| Levels of antioxidant defences are decreased in bovine spermatozoa after a cycle of freezing and thawing.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXhtFeltr8%3D&md5=6150d07dadcd400150da5efb4b089162CAS | 10657047PubMed |
Bilodeau, J. F., Blanchette, S., Cormier, N., and Sirard, M. A. (2002). Reactive oxygen species-mediated loss of bovine sperm motility in egg yolk Tris extender: protection by pyruvate, metal chelators and bovine liver or oviductal fluid catalase. Theriogenology 57, 1105–1122.
| Reactive oxygen species-mediated loss of bovine sperm motility in egg yolk Tris extender: protection by pyruvate, metal chelators and bovine liver or oviductal fluid catalase.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XjslGqtLc%3D&md5=46110663f682b166f3f4086aa028f031CAS | 12041904PubMed |
Brouwers, J. F. H. M., and Gadella, B. M. (2003). In situ detection and localisation of lipid peroxidation in individual bovine sperm cells. Free Radic. Biol. Med. 35, 1382–1391.
| In situ detection and localisation of lipid peroxidation in individual bovine sperm cells.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXpt1equrg%3D&md5=393b2ce57d6081a7f7c4340f6807c7b5CAS |
Cormier, N., and Bailey, J. L. (2003). A differential mechanism is involved during heparin- and cryopreservation-induced capacitation of bovine spermatozoa. Biol. Reprod. 69, 177–185.
| A differential mechanism is involved during heparin- and cryopreservation-induced capacitation of bovine spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXkvFCntL4%3D&md5=228b1559d7d45609a9b72767a8f0d4a3CAS | 12620931PubMed |
Cormier, N., Sirard, M. A., and Bailey, J. L. (1997). Premature capacitation of bovine spermatozoa is initiated by cryopreservation. J. Androl. 18, 461–468.
| 1:STN:280:DyaK2svivFKntw%3D%3D&md5=51d547b80dadae3599b3094f08c250acCAS | 9283961PubMed |
Courtens, J. L., Ekwall, H., Paquignon, M., and Ploen, L. (1989). Preliminary study of water and some element contents in boar spermatozoa, before, during and after freezing. J. Reprod. Fertil. 87, 613–626.
| Preliminary study of water and some element contents in boar spermatozoa, before, during and after freezing.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXhvFektg%3D%3D&md5=e969047d85ec153d1f220f5b62619607CAS | 2600912PubMed |
de Lamirande, E., Jiang, H., Zini, A., Kodama, H., and Gagnon, C. (1997). Reactive oxygen species and sperm physiology. Rev. Reprod. 2, 48–54.
| Reactive oxygen species and sperm physiology.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXhs1Kmsrk%3D&md5=a412b1208babd74336d1817534cb50ccCAS | 9414465PubMed |
Den Daas, J. H. G., De Jong, G., Lansbergen, L. M. T. E., and Van Wagtendonk-De Leeuw, A. M. (1998). The relationship between the number of spermatozoa inseminated and the reproductive efficiency of individual dairy bulls. J. Dairy Sci. 81, 1714–1723.
| The relationship between the number of spermatozoa inseminated and the reproductive efficiency of individual dairy bulls.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXkvVyrtbc%3D&md5=0a57aecce3d6b068a2eacc512ef412f4CAS |
Felipe-Pérez, Y. E., Valencia, J., Juárez-Mosqueda Mde, L., Pescador, N., Roa-Espitia, A. L., and Hernández-González, E. O. (2012). Cytoskeletal proteins f-actin and beta-dystrobrevin are altered by the cryopreservation process in bull sperm. Cryobiology 64, 103–109.
| Cytoskeletal proteins f-actin and beta-dystrobrevin are altered by the cryopreservation process in bull sperm.Crossref | GoogleScholarGoogle Scholar | 22209823PubMed |
Foote, R. H., and Kaproth, M. T. (1997). Sperm numbers inseminated in dairy cattle and non-return rates revisited. J. Dairy Sci. 80, 3072–3076.
| Sperm numbers inseminated in dairy cattle and non-return rates revisited.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXnsFWitLs%3D&md5=8e748e77cd2af4dd828718a04ea09895CAS | 9406102PubMed |
Graham, J. K., and Mocé, E. (2005). Fertility evaluation of frozen–thawed semen. Theriogenology 64, 492–504.
| Fertility evaluation of frozen–thawed semen.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2MzmslKntg%3D%3D&md5=1a3c2d154de198956dc16067db307147CAS | 15946734PubMed |
Guthrie, H. D., and Welch, G. R. (2006). Determination of intracellular reactive oxygen species and high mitochondrial membrane potential in Percoll-treated viable boar sperm using fluorescence-activated flow cytometry. J. Anim. Sci. 84, 2089–2100.
| Determination of intracellular reactive oxygen species and high mitochondrial membrane potential in Percoll-treated viable boar sperm using fluorescence-activated flow cytometry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xot1Onur8%3D&md5=1ea93aa190df43baf35d449d9577ba14CAS | 16864869PubMed |
Hammerstedt, R. H., Graham, J. K., and Nolan, J. P. (1990). Cryopreservation of mammalian sperm: what we ask them to survive. J. Androl. 11, 73–88.
| 1:CAS:528:DyaK3cXhtlKgs7c%3D&md5=ddb5d84960be1c47c8ec8760cf54e6f6CAS | 2179184PubMed |
Holt, W. V., and North, R. D. (1991). Cryopreservation, actin localisation and thermotropic phase transitions in ram spermatozoa. J. Reprod. Fertil. 91, 451–461.
| Cryopreservation, actin localisation and thermotropic phase transitions in ram spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3M7ptl2ksg%3D%3D&md5=e5fb78b2049d02f850bec1e99adf8d10CAS | 2013873PubMed |
Hossain, M. S., Johannisson, A., Wallgren, M., Nagy, S., Siqueira, A. P., and Rodriguez-Martinez, H. (2011). Flow cytometry for the assessment of animal sperm integrity and functionality: state of the art. Asian J. Androl. 13, 406–419.
| Flow cytometry for the assessment of animal sperm integrity and functionality: state of the art.Crossref | GoogleScholarGoogle Scholar | 21478895PubMed |
Hussain, S. A., Lessard, C., and Anzar, M. (2011). Quantification of damage at different stages of cryopreservation of endangered North American bison (Bison bison) semen and the effects of extender and freeze rate on post-thaw sperm quality. Anim. Reprod. Sci. 129, 171–179.
| Quantification of damage at different stages of cryopreservation of endangered North American bison (Bison bison) semen and the effects of extender and freeze rate on post-thaw sperm quality.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC387ntVGluw%3D%3D&md5=c58d041ad927286c3518df0190dfedb1CAS | 22240453PubMed |
John Morris, G., Acton, E., Murray, B. J., and Fonseca, F. (2012). Freezing injury: the special case of the sperm cell. Cryobiology 64, 71–80.
| Freezing injury: the special case of the sperm cell.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhvFKrsrk%3D&md5=2b9c162b7d1e4cced8397f8ff54a752eCAS | 22197768PubMed |
Jones, R. C., and Stewart, D. L. (1979). The effects of cooling to 5 degrees C and freezing and thawing on the ultrastructure of bull spermatozoa. J. Reprod. Fertil. 56, 233–238.
| The effects of cooling to 5 degrees C and freezing and thawing on the ultrastructure of bull spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaE1M3ktFOlug%3D%3D&md5=4cddc951de799dcc2671ae6fa7328ab5CAS | 469847PubMed |
Khan, D. R., Ahmad, N., Anzar, M., and Channa, A. A. (2009). Apoptosis in fresh and cryopreserved buffalo sperm. Theriogenology 71, 872–876.
| Apoptosis in fresh and cryopreserved buffalo sperm.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXitVSgsL4%3D&md5=751cc4bd62ce98d46396830bbd7b324cCAS | 19091389PubMed |
Kim, S. H., Yu, D. H., and Kim, Y. J. (2010). Effects of cryopreservation on phosphatidylserine translocation, intracellular hydrogen peroxide and DNA integrity in canine sperm. Theriogenology 73, 282–292.
| Effects of cryopreservation on phosphatidylserine translocation, intracellular hydrogen peroxide and DNA integrity in canine sperm.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhs1Wgt7fO&md5=0a5acda61969063c44358377a029d553CAS | 19883935PubMed |
Krzyzosiak, J., Molan, P., and Vishwanath, R. (1999). Measurements of bovine sperm velocities under true anaerobic and aerobic conditions. Anim. Reprod. Sci. 55, 163–173.
| Measurements of bovine sperm velocities under true anaerobic and aerobic conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXivFelt7w%3D&md5=a469e31146b6b6e40db687a472f71e87CAS | 10379669PubMed |
Lindemann, C. B., Fisher, M., and Lipton, M. (1982). A comparative study of the effects of freezing and frozen storage on intact and demembranated bull spermatozoa. Cryobiology 19, 20–28.
| A comparative study of the effects of freezing and frozen storage on intact and demembranated bull spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL387mtl2ruw%3D%3D&md5=e9b7151390d12ebc6e817b2a5a9517bcCAS | 7067484PubMed |
Mahfouz, R., Sharma, R., Lackner, J., Aziz, N., and Agarwal, A. (2009). Evaluation of chemiluminescence and flow cytometry as tools in assessing production of hydrogen peroxide and superoxide anion in human spermatozoa. Fertil. Steril. 92, 819–827.
| Evaluation of chemiluminescence and flow cytometry as tools in assessing production of hydrogen peroxide and superoxide anion in human spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXht1GntbjJ&md5=36042aad012c3dd492852f8f7921e9aaCAS | 18710706PubMed |
Makker, K., Agarwal, A., and Sharma, R. (2009). Oxidative stress & male infertility. Indian J. Med. Res. 129, 357–367.
| 1:CAS:528:DC%2BD1MXovFSntr0%3D&md5=e74f6b5bd6fd649b61f8a5fd8532a35bCAS | 19535829PubMed |
Manjunath, P., Chandonnet, L., Leblond, E., and Desnoyers, L. (1994). Major proteins of bovine seminal vesicles bind to spermatozoa. Biol. Reprod. 50, 27–37.
| Major proteins of bovine seminal vesicles bind to spermatozoa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXltVOrtQ%3D%3D&md5=cfb1f4b65e93c09d86d6461b6632d8adCAS | 8312447PubMed |
Martin, G., Sabido, O., Durand, P., and Levy, R. (2004). Cryopreservation induces an apoptosis-like mechanism in bull sperm. Biol. Reprod. 71, 28–37.
| Cryopreservation induces an apoptosis-like mechanism in bull sperm.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXltFKktLo%3D&md5=43fb837e750e9eb8f8d2e6208d123d9aCAS | 14973261PubMed |
Mazur, P. (1980). Fundamental aspects of the freezing of cells with emphasis on mammalian ova and embryos. In ‘9th International Congress on Animal Reproduction and Artificial Insemination, Madrid’. pp. 99–114. (Editorial Garsi: Madrid.)
Mazur, P. (1984). Freezing of living cells: mechanisms and implications. Am. J. Physiol. 247, C125–C142.
| 1:CAS:528:DyaL2cXls1Ors7w%3D&md5=87942b9dbe23f3e309c9d5f31fd208d9CAS | 6383068PubMed |
Nimalaratne, C., Lopes-Lutz, D., Schieber, A., and Wu, J. (2011). Free aromatic amino acids in egg yolk show antioxidant properties. Food Chem. 129, 155–161.
| Free aromatic amino acids in egg yolk show antioxidant properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXmvFymsLs%3D&md5=dfccd49b35b4269876b4ca148e353c68CAS |
Ollero, M., Bescos, O., Cebrian-Perez, J. A., and Muino-Blanco, T. (1998). Loss of plasma membrane proteins of bull spermatozoa through the freezing–thawing process. Theriogenology 49, 547–555.
| Loss of plasma membrane proteins of bull spermatozoa through the freezing–thawing process.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXhtFShu78%3D&md5=a3e057845e1d081e88ee68b1dd131571CAS | 10732034PubMed |
Parks, J. E., and Graham, J. K. (1992). Effects of cryopreservation procedures on sperm membranes. Theriogenology 38, 209–222.
| Effects of cryopreservation procedures on sperm membranes.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvFyqtg%3D%3D&md5=22f5a9073256613559591161ea487013CAS | 16727131PubMed |
Peña, F. J., Johannisson, A., Wallgren, M., and Rodríguez-Martínez, H. (2003). Assessment of fresh and frozen–thawed boar semen using an Annexin-V assay: a new method of evaluating sperm membrane integrity. Theriogenology 60, 677–689.
| Assessment of fresh and frozen–thawed boar semen using an Annexin-V assay: a new method of evaluating sperm membrane integrity.Crossref | GoogleScholarGoogle Scholar | 12832017PubMed |
Pons-Rejraji, H., Bailey, J. L., and Leclerc, P. (2009). Cryopreservation affects bovine sperm intracellular parameters associated with capacitation and acrosome exocytosis. Reprod. Fertil. Dev. 21, 525–537.
| Cryopreservation affects bovine sperm intracellular parameters associated with capacitation and acrosome exocytosis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXksF2ru7w%3D&md5=cf491d4efdd8c93be2b33344440e4b61CAS | 19383259PubMed |
Quinn, P. J. (1989). Principles of membrane stability and phase behaviour under extreme conditions. J. Bioenerg. Biomembr. 21, 3–19.
| Principles of membrane stability and phase behaviour under extreme conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXhtFSiu7k%3D&md5=4df8768072a44ac366bb22a7e8969922CAS | 2651426PubMed |
Rasul, Z., Ahmad, N., and Anzar, M. (2001). Changes in motion characteristics, plasma membrane integrity and acrosome morphology during cryopreservation of buffalo spermatozoa. J. Androl. 22, 278–283.
| 1:STN:280:DC%2BD3M3lvVChsQ%3D%3D&md5=f0913eac0993bfbb6a6a266f68633715CAS | 11229802PubMed |
Schuffner, A., Morshedi, M., Vaamonde, D., Duran, E. H., and Oehninger, S. (2002). Effect of different incubation conditions on phosphatidylserine externalisation and motion parameters of purified fractions of highly motile human spermatozoa. J. Androl. 23, 194–201.
| 1:CAS:528:DC%2BD38XitVWqsLY%3D&md5=afdecfa9c3a16be6873158a369d7d63aCAS | 11868812PubMed |
Shannon, P., and Curson, B. (1972). Toxic effect and action of dead sperm on diluted bovine semen. J. Dairy Sci. 55, 614–620.
| Toxic effect and action of dead sperm on diluted bovine semen.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE38XktFOgur0%3D&md5=4d0796fddfc5de3e67dc79fdca2fca2eCAS | 4623377PubMed |
Suarez, S. S. (2007). Interactions of spermatozoa with the female reproductive tract: inspiration for assisted reproduction. Reprod. Fertil. Dev. 19, 103–110.
| Interactions of spermatozoa with the female reproductive tract: inspiration for assisted reproduction.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2s7ovFKmsA%3D%3D&md5=c139f6636cbe8ba6e3aa5011f0573809CAS | 17389139PubMed |
Suarez, S. S., and Pacey, A. A. (2006). Sperm transport in the female reproductive tract. Hum. Reprod. Update 12, 23–37.
| Sperm transport in the female reproductive tract.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2MnmslSgtA%3D%3D&md5=0bfff1eafe032a1d13d1719d0f265b80CAS | 16272225PubMed |
Visconti, P. E., Krapf, D., de la Vega-Beltran, J. L., Acevedo, J. J., and Darszon, A. (2011). Ion channels, phosphorylation and mammalian sperm capacitation. Asian J. Androl. 13, 395–405.
| Ion channels, phosphorylation and mammalian sperm capacitation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXlsFGrtrc%3D&md5=0fadd9e9078cb2871a623be00fafd279CAS | 21540868PubMed |
Vishwanath, R., and Shannon, P. (1997). Do sperm cells age? A review of the physiological changes in sperm during storage at ambient temperature. Reprod. Fertil. Dev. 9, 321–331.
| Do sperm cells age? A review of the physiological changes in sperm during storage at ambient temperature.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXlsFCisbo%3D&md5=839e1b7f9230f9a4defe88a2add49955CAS | 9261880PubMed |
Vishwanath, R., and Shannon, P. (2000). Storage of bovine semen in liquid and frozen state. Anim. Reprod. Sci. 62, 23–53.
| Storage of bovine semen in liquid and frozen state.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXlt1Kgsbs%3D&md5=3bf83f28a4dd363facd224033bf41b4aCAS | 10924819PubMed |
Watson, P. F. (1995). Recent developments and concepts in the cryopreservation of spermatozoa and the assessment of their post-thawing function. Reprod. Fertil. Dev. 7, 871–891.
| Recent developments and concepts in the cryopreservation of spermatozoa and the assessment of their post-thawing function.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK283ns1alsQ%3D%3D&md5=dc09a0309be5faf6c440f5201a533b66CAS | 8711221PubMed |
Watson, P. F. (2000). The causes of reduced fertility with cryopreserved semen. Anim. Reprod. Sci. 60–61, 481–492.
| The causes of reduced fertility with cryopreserved semen.Crossref | GoogleScholarGoogle Scholar | 10844218PubMed |
Wyllie, A. H., Kerr, J. F., and Currie, A. R. (1980). Cell death: the significance of apoptosis. Int. Rev. Cytol. 68, 251–306.
| Cell death: the significance of apoptosis.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL3M7ptFemtg%3D%3D&md5=eb84019dfe557e34555da9c68e179b99CAS | 7014501PubMed |
Young, D., Fan, M. Z., and Mine, Y. (2010). Egg-yolk peptides up-regulate glutathione synthesis and antioxidant enzyme activities in a porcine model of intestinal oxidative stress. J. Agric. Food Chem. 58, 7624–7633.
| Egg-yolk peptides up-regulate glutathione synthesis and antioxidant enzyme activities in a porcine model of intestinal oxidative stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXnt1CntL8%3D&md5=56cbf8ca1baf2a993c72b476b760c508CAS | 20540508PubMed |
