title: The improving effect of reduced glutathione on boar sperm cryotolerance is related with the intrinsic ejaculate freezability.
abstract: Reduced glutathione (GSH) improves boar sperm cryosurvival and fertilising ability when added to freezing extenders. Poor freezability ejaculates (PFE) are known to present lower resistance than good freezability ejaculates (GFE) to cryopreservation procedures. So far, no study has evaluated whether the ability of GSH to counteract the cryopreservation-induced injuries depends on ejaculate freezability (i.e. GFE vs. PFE). For this reason, thirty boar ejaculates were divided into three equal volume fractions and cryopreserved with or without GSH at a final concentration of either 2 or 5mM in freezing media. Before and after freeze-thawing, sperm quality was evaluated through analysis of viability, motility, integrity of outer acrosome membrane, ROS levels, integrity of nucleoprotein structure, and DNA fragmentation. Ejaculates were classified into two groups (GFE or PFE) according to their post-thaw sperm motility and viability assessments in negative control (GSH 0mM), after running cluster analyses. Values of each sperm parameter were then compared between treatments (GSH 0mM, GSH 2mM, GSH 5mM) and freezability groups (GFE, PFE). In the case of GFE, GSH significantly improved boar sperm cryotolerance, without differences between 2 and 5mM. In contrast, PFE freezability was significantly increased when supplemented with 5mM GSH, but not when supplemented with 2mM GSH. In conclusion, PFE need a higher concentration of GSH than GFE to improve their cryotolerance.
authors: Unit of Animal Reproduction, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, E-08193 Bellaterra (Barcelona), Spain. Electronic address: marc.yeste@uab.cat.
authors: Marc
authors: M
authors: Yeste
authors: Unit of Animal Reproduction, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, E-08193 Bellaterra (Barcelona), Spain.
authors: Efrén
authors: E
authors: Estrada
authors: Biotechnology of Animal and Human Reproduction (TechnoSperm), Department of Biology, Institute of Food and Agricultural Technology, University of Girona, E-17071 Girona, Spain.
authors: Elisabeth
authors: E
authors: Pinart
authors: Biotechnology of Animal and Human Reproduction (TechnoSperm), Department of Biology, Institute of Food and Agricultural Technology, University of Girona, E-17071 Girona, Spain.
authors: Sergi
authors: S
authors: Bonet
authors: Unit of Animal Reproduction, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, E-08193 Bellaterra (Barcelona), Spain.
authors: Jordi
authors: J
authors: Miró
authors: Unit of Animal Reproduction, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, E-08193 Bellaterra (Barcelona), Spain.
authors: Joan E
authors: JE
authors: Rodríguez-Gil
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods* / Q000662:veterinary; D003451:Cryoprotective Agents / Q000737:chemistry* / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology*; D008297:Male; D012662:Semen Preservation / Q000379:methods* / Q000662:veterinary; D034421:Sus scrofa
chemical_list: D003451:Cryoprotective Agents; D005978:Glutathione
keywords: Boar semen; Cryotolerance; Good and poor freezability ejaculates; Reduced glutathione; Sperm cryopreservation