title: The advantages of low-density lipoproteins in the cryopreservation of bull semen.
abstract: Egg low-density lipoprotein (LDL) was added at concentrations (w/v) of 7%, 8% or 9% to the extenders used to freeze bull semen and its effects on seminal parameters and anti-oxidant activities of frozen-thawed sperm were assessed. Analysis of data showed that sperm exposed to 8% LDL exhibited the greatest percentages of sperm motility, acrosome integrity and membrane integrity, compared to the control which differed from the treatment groups by replacing LDL with 20% egg yolk (P<0.05). No difference was observed for membrane integrity between 8% and 9% LDL groups (P>0.05). The extender supplemented with LDL did not exhibit improvement in SOD levels. However, 8% LDL group favored the highest anti-oxidant activities of CAT, GSH-Px and GSH in comparison to other groups (7%, 9% LDL and the control) (P<0.05). No difference was observed for CAT activity between 9% LDL and the control group. In conclusion, sperm cryopreserved in the extender containing 8% LDL in place of egg yolk exhibited the greatest percentages of post-thaw sperm motility, acrosome integrity and membrane integrity, in comparison with the control, and favored the highest anti-oxidant activities of CAT, GSH-Px and GSH in comparison with other groups. The replacement of egg yolk by LDL in the composition of extenders was beneficial for bull sperm cryopreservation.
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Hu
authors.forename: Zhong-Liang
authors.initials: ZL
authors.lastname: Jiang
authors.forename: Rui-Kai
authors.initials: RK
authors.lastname: Lv
authors.forename: Qing-Wang
authors.initials: QW
authors.lastname: Li
authors.forename: Shu-Shan
authors.initials: SS
authors.lastname: Zhang
authors.forename: Lin-Sen
authors.initials: LS
authors.lastname: Zan
authors.forename: Yao-Kun
authors.initials: YK
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Li
mesh_terms: D000177:Acrosome / Q000187:drug effects; D000818:Animals; D000975:Antioxidants; D002374:Catalase / Q000187:drug effects; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods* / Q000662:veterinary; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004530:Egg Yolk / Q000633:toxicity; D005978:Glutathione / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008297:Male; D012661:Semen / Q000187:drug effects / Q000378:metabolism; D012662:Semen Preservation / Q000379:methods* / Q000662:veterinary; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003451:Cryoprotective Agents; D008077:Lipoproteins, LDL; D002374:Catalase; D005979:Glutathione Peroxidase; D005978:Glutathione