title: The Replacement of Monosaccharide by Mannitol or Sorbitol in the Freezing Extender Enhances Cryosurvival of Ram Spermatozoa.
abstract: In this study, the protective effects of monosaccharides (glucose and fructose) and sugar alcohols (mannitol, sorbitol, and xylitol) on frozen ram spermatozoa were evaluated and compared. The motility, moving velocity, and hypoosmotic swelling capability of spermatozoa frozen with monosaccharide or sugar alcohol were measured using a computer-assisted spermatozoa analyzer system. The acrosome status, membrane integrity, distribution of phosphatidylserine (PS), and mitochondrial membrane potential (MMP) were analyzed using fluorescence staining and flow cytometry. The results indicated that similar to glucose or fructose, the presence of sugar alcohol in the freezing extender cannot significantly improve the motility and moving velocity of ram spermatozoa equilibrated at 5°C. In terms of motility, pathway velocity, curve velocity, hypoosmotic swelling capability, acrosome and membrane integrity, and MMP, the inclusion of mannitol or sorbitol in the extender can significantly improve the quality of frozen-thawed ram spermatozoa compared to glucose or fructose. However, the effects of mannitol or sorbitol on linear velocity and PS distribution of frozen-thawed spermatozoa were similar to those of the monosaccharides (p > 0.05). In addition, the ability of xylitol to protect acrosome and maintain MMP in frozen-thawed spermatozoa was significantly higher compared with glucose or fructose (p < 0.05), although it could not improve the other evaluated parameters. Finally, there is no significant difference existing between mannitol and sorbitol with respect to the above evaluated parameters. In conclusion, the replacement of glucose or fructose by mannitol or sorbitol in a freezing extender can improve the postthaw quality of ram spermatozoa under specific freezing conditions. Moreover, the protective effects of mannitol and sorbitol on frozen-thawed ram spermatozoa are superior to that of xylitol. However, in the presence of sugar alcohols, the cryoinjury on spermatozoa membrane is still serious. In the future, the question of protecting the membrane of frozen-thawed spermatozoa needs further research.
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Guo Quan
authors.initials: GQ
authors.lastname: Wu
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Chun Rong
authors.initials: CR
authors.lastname: Lv
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Yan Ting
authors.initials: YT
authors.lastname: Jiang
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Si Yu
authors.initials: SY
authors.lastname: Wang
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Qing Yong
authors.initials: QY
authors.lastname: Shao
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Qiong Hua
authors.initials: QH
authors.lastname: Hong
authors.affiliation: 1 Yunnan Animal Science and Veterinary Institute , Kunming City, China .|2 Yunnan Provincial Engineering Laboratory of Animal Genetic Resource Conservation and Germplasm Enhancement , Kunming City, China .|3 Yunnan Provincial Meat Caprine Engineering Research Center , Kunming City, China .
authors.forename: Guo Bo
authors.initials: GB
authors.lastname: Quan
mesh_terms: D000177:Acrosome / Q000187:drug effects; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods* / Q000662:veterinary; D003451:Cryoprotective Agents / Q000494:pharmacology*; D005615:Freezing; D008297:Male; D008353:Mannitol / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009005:Monosaccharides / Q000494:pharmacology; D012662:Semen Preservation / Q000379:methods* / Q000662:veterinary; D012756:Sheep; D013012:Sorbitol / Q000494:pharmacology*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*; D014993:Xylitol / Q000494:pharmacology
chemical_list: D003451:Cryoprotective Agents; D009005:Monosaccharides; D008353:Mannitol; D013012:Sorbitol; D014993:Xylitol
keywords: cryopreservation; mannitol; monosaccharide; ram spermatozoa; sorbitol