title: Liposomes as an alternative to egg yolk in stallion freezing extender.
abstract: Egg yolk is normally used as a protective agent to freeze semen of equine and other species. However, addition of egg yolk in extenders is not without disadvantages and the demand to find cryoprotective alternatives is strong. The objective of this study was to test the cryoprotective capacities of liposomes composed of egg yolk phospholipids. Two experiments were conducted: 1) the first to determine the optimal composition and concentration of liposomes to preserve post-thaw motility and membrane integrity of spermatozoa; 2) the second to assess in vivo the cryoprotective capacities of these liposomes. In Experiment 2, post-thaw motility and membrane integrity of spermatozoa were also analyzed. Experiment 1 demonstrated that liposomes composed of phospholipids E80 (commercial lecithins from egg yolk composed mainly of phosphatidylcholine and phosphatidylethanolamine) and of Hank's salts-glucose-lactose solution (E80-liposomes) were the most efficient in preserving post-thaw motility. The optimal concentration was 4 % (v/v). In Experiment 2, fertility rate after artificial insemination of semen frozen with E80-liposomes was 55 % (22/40) compared with 68 % (27/40) with the control extender containing egg yolk (EY) (p = 0.23). Post-thaw motility parameters were higher with EY than with E80-liposomes (p < 0.0001). For post-thaw membrane integrity no difference was observed between the two extenders (p = 0.08). Liposomes composed of egg yolk phospholipids appeared to be a promising alternative to replace egg yolk in semen freezing extenders in equine species.
authors.affiliation: INRA, UMR85 Physiologie de la Reproduction et des Comportements, Nouzilly, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Pillet
authors.forename: Catherine
authors.initials: C
authors.lastname: Labbe
authors.forename: Florence
authors.initials: F
authors.lastname: Batellier
authors.forename: Guy
authors.initials: G
authors.lastname: Duchamp
authors.forename: Valérie
authors.initials: V
authors.lastname: Beaumal
authors.forename: Marc
authors.initials: M
authors.lastname: Anton
authors.forename: Serge
authors.initials: S
authors.lastname: Desherces
authors.forename: Eric
authors.initials: E
authors.lastname: Schmitt
authors.forename: Michèle
authors.initials: M
authors.lastname: Magistrini
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000737:chemistry*; D004530:Egg Yolk / Q000737:chemistry*; D005260:Female; D006736:Horses; D007315:Insemination, Artificial / Q000662:veterinary; D008081:Liposomes / Q000737:chemistry*; D008297:Male; D010743:Phospholipids; D011247:Pregnancy; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility
chemical_list: D003451:Cryoprotective Agents; D008081:Liposomes; D010743:Phospholipids