Thomson Laura Kelly, Fleming Steven Denis, Schulke Lauren, Barone Katrina, Zieschang Julie-Anne, Clark Anne Melton
Fertility First, Hurstville, Australia.
Department of Obstetrics and Gynecology, Westmead Hospital, University of Sydney, Sydney, Australia.
Fertil Steril. 2009 Sep;92(3):991-1001. doi: 10.1016/j.fertnstert.2008.07.1747. Epub 2008 Sep 14.
To investigate and compare seven different commercially available cryoprotectant media in terms of the DNA integrity of spermatozoa recovered after cryopreservation and separation using density gradient centrifugation (DGC).
A prospective clinical study.
Tertiary care fertility clinic.
PATIENT(S): Three hundred twenty men presenting for infertility investigations.
INTERVENTION(S): Each sample was randomly assigned to one of seven commercially available cryoprotectants or to no cryoprotectant.
MAIN OUTCOME MEASURE(S): Percentage sperm DNA fragmentation after cryopreservation and preparation using DGC.
RESULT(S): The mean percentage fragmentation was significantly higher post-thaw and post-DGC; however, some patients (26.3%) demonstrated a lower percentage fragmentation post-thaw. No single cryoprotectant was identified as the best at preserving DNA integrity. The difference in fragmentation after thawing and DGC was found to be highly dependent on the prefreeze fragmentation. Motility was also significantly correlated with the difference in fragmentation post-thaw (r = -0.161).
CONCLUSION(S): Neither the presence nor type of cryoprotectant affects the DNA integrity of spermatozoa after cryopreservation and DGC. Individuals with lower prefreeze fragmentation in DGC-prepared spermatozoa have larger increases in fragmentation and are less likely to exhibit lower levels of fragmentation post-thaw. The reverse effect observed in those with higher prefreeze fragmentation gives rise to a possible novel method of reducing fragmentation in sperm used for assisted reproductive technology treatment cycles without the need for testicular sperm retrievals.
研究并比较七种市售冷冻保护剂培养基，这些培养基用于冷冻保存及密度梯度离心（DGC）分离后回收精子的DNA完整性。
前瞻性临床研究。
三级医疗生殖诊所。
320名前来进行不育症检查的男性。
每个样本被随机分配至七种市售冷冻保护剂之一或不使用冷冻保护剂。
冷冻保存及使用DGC制备后精子DNA片段化的百分比。
解冻后和DGC处理后的平均片段化百分比显著更高；然而，一些患者（26.3%）解冻后的片段化百分比更低。未发现单一冷冻保护剂在保存DNA完整性方面表现最佳。解冻和DGC处理后片段化的差异被发现高度依赖于冷冻前的片段化情况。活力也与解冻后片段化的差异显著相关（r = -0.161）。
冷冻保护剂的存在与否及类型均不影响冷冻保存和DGC处理后精子的DNA完整性。DGC制备的精子冷冻前片段化较低的个体，片段化增加幅度更大，解冻后片段化水平较低的可能性更小。在冷冻前片段化较高的个体中观察到的相反效应，可能产生一种新方法，可在无需睾丸精子提取的情况下，减少辅助生殖技术治疗周期中使用的精子的片段化。
