PDF(Pubmed)
Abstract：
Cryopreservation of human spermatozoa is a necessity for males suffering from infertility who cannot produce fresh semen for insemination. However, current ART cryopreservation protocols are associated with losses of sperm motility, vitality and DNA integrity, which are thought to be linked to the induction of oxidative damage and the toxic properties of commercial cryoprotectants (CPAs). Preventing or mitigating these losses would be hugely beneficial to sperm survival during ART. Therefore, in this in vitro investigation, lipid peroxidation, production of reactive oxygen species, movement characteristics, antioxidant capacity, vitality, and DNA integrity were examined in semen samples both pre- and post-cryopreservation with CPA supplementation. The findings revealed a 50% reduction in antioxidant capacity with CPA addition, which was accompanied by significant increases in generation of reactive oxygen species and formation of lipid aldehydes. These changes were, in turn, correlated with reductions in sperm viability, motility and DNA integrity. Antioxidant supplementation generated bell-shaped dose-response curves with both resveratrol and vitamin C, emphasising the vulnerability of these cells to both oxidative and reductive stress. At the optimal dose, vitamin C was able to significantly enhance vitality and reduce DNA damage recorded in cryopreserved human spermatozoa. An improvement in sperm motility did not reach statistical significance, possibly because additional pathophysiological mechanisms limit the potential effectiveness of antioxidants in rescuing this aspect of sperm function. The vulnerability of human spermatozoa to reductive stress and the complex nature of sperm cryoinjury will present major challenges in creating the next generation of cryoprotective media.
摘要：
人类精子的冷冻保存对于患有不育症的男性来说是必需的，他们不能产生用于授精的新鲜精液。然而,目前的ART冷冻保存方案与精子活力的丧失有关，活力和DNA完整性，被认为与氧化损伤的诱导和商业冷冻保护剂（CPAs）的毒性有关。预防或减轻这些损失将对ART期间的精子存活非常有益。因此,在这项体外研究中，脂质过氧化，活性氧的产生，运动特性，抗氧化能力，活力,在补充CPA的冷冻保存前和冷冻后检查精液样品中的DNA完整性。研究结果表明，添加CPA后，抗氧化能力降低了50%，伴随着活性氧的产生和脂质醛的形成显着增加。这些变化是，反过来,与精子活力降低相关，运动性和DNA完整性。抗氧化剂补充产生钟形的剂量反应曲线与白藜芦醇和维生素C,强调这些细胞对氧化和还原性应激的脆弱性。在最佳剂量下，维生素C能够显着增强活力并减少冷冻保存的人类精子中记录的DNA损伤。精子活力的改善没有达到统计学意义，可能是因为其他病理生理机制限制了抗氧化剂在挽救精子功能方面的潜在有效性。人类精子对还原性应激的脆弱性和精子冷冻损伤的复杂性将在创造下一代冷冻保护介质方面提出重大挑战。
