Zini A, Finelli A, Phang D, Jarvi K
Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
Urology. 2000 Dec 20;56(6):1081-4. doi: 10.1016/s0090-4295(00)00770-6.
To compare the effects of density-gradient centrifugation and swim-up technique on sperm DNA integrity.
Semen samples (n = 22) were obtained from consecutive nonazoospermic men presenting for infertility evaluation. Individual samples were divided into three aliquots (whole semen, density-gradient centrifugation, and swim-up) for subsequent analysis of sperm motility and DNA integrity. Sperm DNA integrity was evaluated by flow cytometry analysis of acridine orange-treated spermatozoa and expressed as the percentage of spermatozoa demonstrating denatured DNA.
Mean sperm motility (+/-SEM) improved significantly after processing with two-layer density-gradient and swim-up compared with whole semen (65.6% +/- 4.0% and 73.0% +/- 3.0% versus 52.0% +/- 3.6%, respectively, P <0.005), with no significant difference in motility between Percoll-treated and swim-up-treated spermatozoa. In contrast, the percentage of spermatozoa with denatured DNA was reduced significantly in swim-up-treated but not in Percoll-treated spermatozoa compared with whole semen (4.8% +/- 1. 2% and 13.6% +/- 3.6% versus 10.1% +/- 2.3%, respectively, P <0. 0001).
Although density-gradient centrifugation is comparable to swim-up technique in recovering spermatozoa with enhanced motility, spermatozoa recovered after swim-up possess higher DNA integrity. These data urge us to reexamine our current sperm processing techniques in order to minimize sperm DNA damage.
比较密度梯度离心法和上游法对精子DNA完整性的影响。
从连续前来进行不育评估的非无精子症男性中获取精液样本（n = 22）。将每个样本分成三等份（全精液、密度梯度离心法处理样本和上游法处理样本），用于后续精子活力和DNA完整性分析。通过吖啶橙处理精子的流式细胞术分析评估精子DNA完整性，并以显示变性DNA的精子百分比表示。
与全精液相比，经双层密度梯度离心法和上游法处理后，精子平均活力（±标准误）显著提高（分别为65.6%±4.0%和73.0%±3.0%，而全精液为52.0%±3.6%，P<0.005），Percoll处理的精子和上游法处理的精子在活力上无显著差异。相比之下，与全精液相比，上游法处理的精子中显示变性DNA的精子百分比显著降低（分别为4.8%±1.2%和13.6%±3.6%，而全精液为10.1%±2.3%，P<0.0001），而Percoll处理的精子中该百分比未显著降低。
虽然密度梯度离心法在回收活力增强的精子方面与上游法相当，但上游法回收的精子具有更高的DNA完整性。这些数据促使我们重新审视当前的精子处理技术，以尽量减少精子DNA损伤。
