Kim J G, Parthasarathy S
Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Semin Reprod Endocrinol. 1998;16(4):235-9. doi: 10.1055/s-2007-1016283.
The unusually high content of phospholipid-bound polyunsaturated fatty acids (PUFA) in the sperm plasma membrane drew attention to their potential physiological significance. Docosahexaenoic acid (22:6) is quantitatively the most important fatty acid. The high PUFA content of sperm membranes makes them vulnerable to peroxidative changes, since PUFA containing two or more double bonds are readily attacked by oxygen radicals. The effects of oxidation on sperm function have been suggested as detrimental as well as beneficial. Generation of reactive oxygen species (ROS) and peroxidation of sperm membrane can bring negative effects on motility, midpiece abnormalities, and sperm-oocyte fusion. ROS trigger sperm hyperactivation, and may support the capacitation of spermatozoa and fertilization. Spermatozoa are protected by various antioxidants and antioxidant enzymes in the seminal plasma or in spermatozoa itself. When the gametes are cultured in vitro, they become more susceptible to oxidative damage. Addition of antioxidants in the media brought beneficial effects in preventing loss of motility and inhibiting lipid peroxidation. Treating patients with antioxidants has shown to have a positive effect on improving fertilization in limited data. The mechanism of antioxidant effects on spermatozoa needs to be further studied.
精子质膜中磷脂结合的多不饱和脂肪酸（PUFA）含量异常高，这使其潜在的生理意义受到关注。二十二碳六烯酸（22:6）在数量上是最重要的脂肪酸。精子膜中高含量的PUFA使其易发生过氧化变化，因为含有两个或更多双键的PUFA很容易受到氧自由基的攻击。氧化对精子功能的影响既有有害的一面，也有有益的一面。活性氧（ROS）的产生和精子膜的过氧化会对精子活力、中段异常以及精卵融合产生负面影响。ROS会引发精子超活化，可能还会支持精子获能和受精。精子在精浆或精子自身中受到各种抗氧化剂和抗氧化酶的保护。当配子在体外培养时，它们更容易受到氧化损伤。在培养基中添加抗氧化剂对防止精子活力丧失和抑制脂质过氧化有有益作用。在有限的数据中，用抗氧化剂治疗患者已显示出对改善受精有积极作用。抗氧化剂对精子的作用机制有待进一步研究。
