线粒体靶向抗氧化剂Mitoquinone对湖羊冻精损伤的保护作用

旨在研究线粒体靶向抗氧化剂Mitoquinone（MitoQ）对湖羊冷冻精子的保护作用。本研究选择健康的成年种公羊精液，将其分成6等份。不含MitoQ者设为对照组（M0），M1、M2、M3、M4和M5组分别为含50、100、150、200和400 nmol·L^-1MitoQ的添加组。精子经冷冻解冻后检测活率、活力、质膜完整率、顶体完整率和线粒体活性等精子质量指标，同时进行超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、活性氧（ROS）、丙二醛（MDA）等抗氧化指标检测。结果表明，当MitoQ添加的浓度为150 nmol·L^-1（M3组）时，其解冻后精子的活率、活力、质膜完整率、顶体完整率和线粒体活性最高，分别达55.00%、52.34%、48.32%、54.51%和51.28%，其线粒体活性显著高于其他组（P<0.05）。M3组解冻后精子的SOD和GSH-Px值分别为203.90 U·mL^-1和123.62 U·L^-1，两者均显著高于M0、M1、M4和M5组（P<0.05）；M3组解冻后精子的ROS和MDA值分别为298.34 U·mL^-1和4.99 nmol·L^-1，显著低于其他组（P<0.05）。当MitoQ的添加浓度提高至200（M4组）和400 nmol·L^-1（M5组）时，冻精质量开始下降，并表现为对精子的氧化损伤。在湖羊冷冻精液中，添加150 nmol·L^-1的MitoQ可显著降低精子氧化损伤，提高冻精品质，当MitoQ的添加浓度超过200 nmol·L^-1时对冷冻精子没有保护作用。

Protective Effect of Mitochondria-targeted Antioxidant Mitoquinone on the Damage of Hu Sheep Frozen Sperm

The purpose of this study was to explore the protective effect of mitochondria-targeted antioxidant Mitoquinone (MitoQ) on frozen sperm of Hu sheep. The semen of healthy adult rams was equally divided into 6 groups. M0, M1, M2, M3, M4 and M5 were the groups containing 0, 50, 100, 150, 200 and 400 nmol·L^-1 MitoQ in semen,respectively. After freezing and thawing, the sperm quality indexes, such as motility, viability, plasma integrity, acrosome integrity and mitochondrial activity, and antioxidative parameters, such as SOD, GSH-Px, ROS and MDA were detected. The results showed that the thawed 150 nmol·L^-1 MitoQ addition group (M3 group) got the highest motility, viability, plasma integrity, acrosome integrity and mitochondrial activity of thawed sperm, which were 55.00%, 52.34%, 48.32%, 54.51% and 51.28%, respectively. And the mitochondrial activity in M3 group was significantly higher than those in the other groups(P<0.05). The SOD and GSH-Px values of thawed sperm in M3 group were 203.90 U·mL^-1 and 123.62 U·L^-1, which were higher than those in M0, M1,M4 and M5 groups(P<0.05). The ROS and MDA values of thawed sperm in M3 group were 298.34 U·mL^-1 and 4.99 nmol·L^-1, which were significantly lower than those in the other groups(P<0.05). When the MitoQ concentration was 200 (M4 group) and 400 nmol·L^-1 (M5 group), the quality of frozen sperm began to decline and showed oxidative damage to sperm. In conclusion, during the freezing of Hu sheep sperm, 150 nmol·L^-1 MitoQ addition in the diluent could reduce sperm oxidative damage and improve frozen sperm quality. Further increasing the MitoQ concentration to more than 200 nmol·L^-1 had no protective effect on frozen semen of Hu sheep.