Rarani Fahimeh Zamani, Golshan-Iranpour Farhad, Dashti Gholam Reza
Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Saint Maryam Fertility and Infertility Center, Shahid Beheshti Hospital, Isfahan, Iran.
Cell Tissue Bank. 2019 Sep;20(3):367-378. doi: 10.1007/s10561-019-09775-6. Epub 2019 May 28.
Cryopreservation exposes sperm to physical and chemical stresses causing cell damages and impairs sperm functions. The aim of this study was to evaluate the association between motility and sperm chromatin/DNA damage before and after cryopreservation and investigate the effects of folic acid and nicotinic acid on post-thaw sperm quality. Thirty semen samples were obtained from 30 normozoospermic men, aged between 25 and 45 years old. Each sample were divided into five aliquots to form the following groups: fresh, cryopreserved with sperm-freeze only (control), with nicotinic acid (10 mM), with folic acid (50 nM), and with a combination of folic acid (50 nM) + nicotinic acid (10 mM). Sperm viability and motility in each group were assessed by eosin-nigrosine staining and computer-aided sperm analysis respectively. Sperm chromatin quality was studied by aniline blue, toluidine blue, acridine orange staining methods and sperm chromatin dispersion test. Cryopreservation led to a significant reduction in sperm quality in comparison to fresh sample groups (p < 0.05). Sperm chromatin damage was negatively correlated with the percentage of progressively motile cells. Supplementation of the cryopreservation medium with folic acid or nicotinic acid induced a significant improvement in sperm parameters and chromatin quality, compared to control groups (p < 0.05). Meanwhile, the combination of folic acid + nicotinic acid showed a significant protective effect in post thaw sperm. In conclusion, cryopreservation generated oxidative stress, inducingsperm cryodamage, reducing progressive motility and sperm quality, as an indicator of significant chromatin/DNA damage. Folic acid and nicotinic acid exhibited a potential cryoprotective effect by enhancing sperm quality.
冷冻保存会使精子受到物理和化学应激，从而导致细胞损伤并损害精子功能。本研究的目的是评估冷冻保存前后精子活力与精子染色质/DNA损伤之间的关联，并研究叶酸和烟酸对解冻后精子质量的影响。从30名年龄在25至45岁之间的正常精子男性中获取了30份精液样本。每份样本被分成五等份，形成以下几组：新鲜组、仅用精子冷冻剂冷冻保存的组（对照组）、添加烟酸（10 mM）的组、添加叶酸（50 nM）的组以及添加叶酸（50 nM）+烟酸（10 mM）组合的组。分别通过伊红-苯胺黑染色和计算机辅助精子分析评估每组中的精子活力和运动能力。通过苯胺蓝、甲苯胺蓝、吖啶橙染色方法和精子染色质扩散试验研究精子染色质质量。与新鲜样本组相比，冷冻保存导致精子质量显著降低（p<0.05）。精子染色质损伤与进行性运动细胞的百分比呈负相关。与对照组相比，在冷冻保存培养基中添加叶酸或烟酸可显著改善精子参数和染色质质量（p<0.05）。同时，叶酸+烟酸的组合对解冻后的精子显示出显著的保护作用。总之，冷冻保存产生氧化应激，诱导精子冷冻损伤，降低进行性运动能力和精子质量，这是显著染色质/DNA损伤的一个指标。叶酸和烟酸通过提高精子质量表现出潜在的冷冻保护作用。
