Buranaamnuay K
Reproductive Medicine Research Group, Institute of Molecular Biosciences (MB), Mahidol University, Nakhon Pathom, Thailand.
Anim Reprod Sci. 2018 Apr;191:56-63. doi: 10.1016/j.anireprosci.2018.02.008. Epub 2018 Feb 12.
The quality of cat epididymal sperm cryopreserved and stored by four methods was assessed. Epididymal sperm were suspended in Tris-glucose-citrate egg yolk extender, loaded in 0.25 mL straws and then cryopreserved. The samples in a standard protocol (LN) were cryopreserved and stored in liquid nitrogen (LN). The sperm straws in the LN-Fr-LN group were cryopreserved in LN and stored in a -75 °C freezer; the straws were returned to LN prior to thawing. The loaded straws in the Fr group were transferred directly from 4 °C to the freezer and maintained in the freezer until thawing. The Fr-LN samples were cryopreserved and stored in the freezer and were introduced into LN before thawing. The sperm thawing was conducted on days 30, 60, 90 and 120 of cryopreservation. The sperm motility, viability, membrane integrity and acrosome integrity were evaluated at 15 and 180 min after thawing. The quality of post-thaw sperm in all three modified protocols was comparable (P > 0.05) and did not differ from that in the standard protocol except the membrane integrity of the 60 days stored samples evaluated at 15 min after thawing, which was significantly higher for the LN-Fr-LN than the Fr-LN groups (P = 0.04). The length of cryopreservation time had no effect (P > 0.05) on the sperm parameters assessed at 15 min after thawing. The sperm motility was significantly greater (P = 0.01 to P = 0.02) for the 15 min than the 180 min incubation. In conclusion, cat epididymal sperm could alternatively be cryopreserved and/or stored by using the -75 °C freezer for 120 days. To use, the cryopreserved sperm in the freezer could be thawed immediately or after being transferred to LN. This was useful for the application of the -75 °C cryopreserved sperm in remote areas.
评估了用四种方法冷冻保存的猫附睾精子的质量。将附睾精子悬浮于Tris-葡萄糖-柠檬酸盐蛋黄稀释液中，装入0.25 mL细管后进行冷冻保存。按照标准方案（LN）的样本冷冻保存于液氮（LN）中。LN-Fr-LN组的精子细管先在液氮中冷冻保存，然后置于-75°C冰箱中；解冻前再放回液氮中。Fr组装入细管的样本直接从4°C转移至冰箱并在冰箱中保存直至解冻。Fr-LN样本先冷冻保存于冰箱中，解冻前再放入液氮中。在冷冻保存的第30、60、90和120天进行精子解冻。在解冻后15分钟和180分钟评估精子活力、存活率、膜完整性和顶体完整性。除了解冻后15分钟评估的保存60天样本的膜完整性外，所有三种改良方案解冻后精子的质量相当（P>0.05），与标准方案无差异，其中LN-Fr-LN组的该指标显著高于Fr-LN组（P=0.04）。冷冻保存时间长短对解冻后15分钟评估的精子参数无影响（P>0.05）。孵育后15分钟的精子活力显著高于180分钟（P=0.01至P=0.02）。总之，猫附睾精子可以用-75°C冰箱冷冻保存和/或储存120天。使用时，冰箱中冷冻保存的精子可以立即解冻，也可以转移至液氮后解冻。这对于偏远地区应用-75°C冷冻保存的精子很有用。
