白藜芦醇对绵羊冷冻精液质量的影响

试验旨在研究白藜芦醇对绵羊冷冻精液质量的改善效果。采用假阴道法采集6只云南半细毛羊精液，用含不同浓度（0、0.1、1、10、20 μmol/L）白藜芦醇的Optidyl稀释液稀释后进行细管分装，低温平衡和液氮气相预冻后，在液氮中保存30 d。解冻后测定精子活力、质膜完整性、磷脂酰丝氨酸（PS）分布、顶体完整性和活性氧等指标。结果表明，解冻后10 μmol/L白藜芦醇组精子总活力、直线运动百分率、精子弯尾率分别为76.14%±0.97%、43.56%±0.91%、43.24%±1.68%，均显著高于其他各组（P<0.05）；而20 μmol/L白藜芦醇组精子总活力、直线运动百分率、精子弯尾率分别为21.78%±0.79%、25.23%±1.34%、4.84%±0.68%，均显著低于其他各组（P<0.05）。10 μmol/L白藜芦醇组精子顶体完整性最高，为50.47%±0.91%，显著高于其他各处理组（P<0.05）。PS分布结果表明，10 μmol/L白藜芦醇组正常精子百分率为46.43%±2.95%，显著高于20 μmol/L组（31.14%±3.56%，P<0.05），与其他各组无显著性差异（P>0.05）。20 μmol/L白藜芦醇组PS标记率（39.82%±3.38%）显著高于其他处理组（P<0.05）。活性氧试验结果表明，10 μmol/L白藜芦醇组正常精子（63.57%±0.71%）显著高于其他各组（P<0.05）；而20 μmol/L白藜芦醇组正常精子（32.45%±1.42%）显著低于其他各组（P<0.05）。综上，在冷冻稀释液中添加白藜芦醇可以改善绵羊冷冻精液品质，这与白藜芦醇的抗氧化特性有关。但是，白藜芦醇的冷冻保护效果具有明显的浓度依赖性，其最佳作用浓度为10 μmol/L，过高浓度的白藜芦醇反而加重精子的冷冻损伤。此外，对于白藜芦醇对绵羊精子的抗冻保护效果仍然需要体外受精或人工授精验证。

The Effects of Resveratrol on the Quality of Frozen Sheep Semen

The effects of resveratrol on the quality of frozen-thawed sheep semen were studied in this study.Semen was collected from six Yunnan semi-fine wool sheep using artificial vagina.The semen was diluted with the Optidyl extender supplemented with resveratrol with a concentration of 0,0.1,1,10,or 20 μmol/L,followed by loading into plastic straws and equilibration at a low temperature.Then,the straws were pre-frozen in liquid nitrogen vapor,followed by storage in liquid nitrogen for 30 days.After thawing for 30 seconds in a 37 ℃ water bath,the parameters including sperm motility,acrosome integrity,membrane integrity,distribution of phosphatidylserine (PS) and ROS were measured.The results showed that the post-thaw sperm total motility,progressive motility and the rate of sperm with curved tail were 76.14%±0.97%,43.56%±0.91% and 43.24%±1.68% in the 10 μmol/L resveratrol group,respectively,which were significantly higher than those in the other groups (P<0.05).However,when the concentration of resveratrol in the freezing extender was 20 μmol/L,the post-thaw total motility,progressive motility and the rate of sperm with curved tail were 21.78%±0.79%,25.23%±1.34% and 4.84%±0.68%,respectively,which were significantly lower than those in the other groups (P<0.05).The acrosome integrity of sperm frozen in the 10 μmol/L resveratrol group was best,which was 50.47%±0.91% and significantly higher than the other treatments (P<0.05).The results of PS distribution showed that the percentage of viable sperm in the 10 μmol/L resveratrol group was 46.43%±2.95%,and significantly higher than that in the 20 μmol/L group (31.14%±3.56%,P<0.05),but there was no significant difference with the other groups (P>0.05).In addition,the PS labeling rate of sperm in the 20 μmol/L resveratrol group (39.82%±3.38%) was significantly higher than those of the other groups (P<0.05).In terms of ROS production,this study demonstrated that the rate of viable sperm (ROS and PI were negative) in the 10 μmol/L resveratrol group (63.57%±0.71%) was significantly higher than that of the other groups (P<0.05),while the rate of viable sperm (32.45%±1.42%) in the 20 μmol/L resveratrol group was significantly lower than those of the other groups (P<0.05).In conclusion,the post-thaw quality of sheep semen could be improved after the addition of resveratrol to the freezing extenders,which might be related to the antioxidant properties of resveratrol.But,the cryoprotective effects of resveratrol dependents on its used doses,and the optimal concentration was 10 μmol/L based on this present study.However,excessively high concentration of resveratrol could aggravate cryodamage on sperm.In addition,the protective effects of resveratrol on sheep sperm still needs to be verified by in vitro fertilization and artificial insemination.