title: Cryopreservation with α-tocopherol and Sephadex filtration improved the quality of boar sperm.
abstract: The objectives were to evaluate postthaw sperm quality and the response to an inducer of in vitro sperm capacitation in boar sperm, cryopreserved with (T) or without (C) α-tocopherol. Boar sperm frozen in 0.2-mL pellets were thawed and washed (W) or selected by three methods: Percoll discontinuous gradient (PS) or Sephadex (Sigma-Aldrich, St. Louis, MO, USA) (neutral [S] or with ion exchange [S+IO] columns). All separation methods enhanced sperm motility, plasma membrane integrity, and functionality and acrosome integrity for both C and T samples (P < 0.05). The best results were obtained with S and ionic Sephadex column. There was a decrease (P < 0.05) in capacitation-like changes in C samples separated with Sephadex (W: 19 ± 0.9%, PS: 22 ± 2.5%, S: 17 ± 1.2%, and S+IO: 17 ± 2.0%). Cryopreservation with α-tocopherol decreased (P < 0.05) the percentage of cryocapacitated sperm (W: 14 ± 0.7%, PS: 14 ± 1.0%, S: 13 ± 1.0%, and S+IO: 14 ± 0.9%) compared with C samples, without differences among selection techniques. Freezing with α-tocopherol and subsequent selection decreased lipid peroxidation (W: 20.79 ± 2.64 nmol thiobarbituric acid reactive substances (TBARS)/10(8) sperm; PS: 13.15 ± 2.39 nmol TBARS/10(8) sperm; S: 13.20 ± 2.18 nmol TBARS/10(8) sperm, and S+IO: 13.62 ± 2.76 nmol TBARS/10(8) sperm), with respect to washed and selected C samples (W: 37.69 ± 5.34 nmol TBARS/10(8) sperm, PS: 25.61 ± 5.85 nmol TBARS/10(8) sperm, S: 19.16 ± 3.28 nmol TBARS/10(8) sperm, and S+IO: 22.16 ± 6.09 nmol TBARS/10(8) sperm). In vitro capacitation levels were significantly higher for neutral Sephadex-selected T samples in comparison with C and unselected samples. These results were confirmed with a follicular fluid-induced acrosome reaction. In conclusion, cryopreserved sperm with α-tocopherol and subsequent Sephadex selection, improved postthaw quality and functionality of boar sperm, which could be useful for assisted reproductive techniques.
authors.affiliation: Area of Biochemistry, INITRA, School of Veterinary Sciences, University of Buenos Aires, Buenos Aires, Argentina. msatorre@fvet.uba.ar
authors.forename: M M
authors.initials: MM
authors.lastname: Satorre
authors.forename: E
authors.initials: E
authors.lastname: Breininger
authors.forename: M T
authors.initials: MT
authors.lastname: Beconi
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D002469:Cell Separation / Q000379:methods / Q000662:veterinary; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel / Q000662:veterinary*; D002852:Chromatography, Ion Exchange / Q000662:veterinary; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003911:Dextrans; D008297:Male; D011205:Povidone; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D012822:Silicon Dioxide; D013075:Sperm Capacitation; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology* / Q000648:ultrastructure; D013552:Swine; D024502:alpha-Tocopherol
chemical_list: D003911:Dextrans; C016039:Percoll; D012822:Silicon Dioxide; C025614:sephadex; D011205:Povidone; D024502:alpha-Tocopherol