Catalán Jaime, Papas Marion, Gacem Sabrina, Mateo-Otero Yentel, Rodríguez-Gil Joan E, Miró Jordi, Yeste Marc
Equine Reproduction Service, Department of Animal Medicine and Surgery, Faculty of Veterinary Sciences, Autonomous University of Barcelona, ES-08193 Bellaterra (Cerdanyola del Vallès), Spain.
Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain.
Biology (Basel). 2020 Aug 29;9(9):254. doi: 10.3390/biology9090254.
Previous studies in other mammalian species have shown that stimulation of semen with red-light increases sperm motility, mitochondrial activity, and fertilizing capacity. This study sought to determine whether red-light stimulation using a light emitting diode (LED) at 620-630 nm affects sperm motility and structure of motile subpopulations, sperm viability, mitochondrial activity, intracellular ATP levels, rate of O consumption and DNA integrity of horse spermatozoa. For this purpose, nine ejaculates were collected from nine different adult stallions. Upon collection, semen was diluted in Kenney extender, analyzed, its concentration was adjusted, and finally it was stimulated with red-light. In all cases, semen was packaged in 0.5-mL transparent straws, which were randomly divided into controls and 19 light-stimulation treatments; 6 consisted of a single exposure to red-light, and the other 13 involved irradiation with intervals of irradiation and darkness (light-dark-light). After irradiation, sperm motility was assessed using a Computerized Semen Analysis System (CASA). Flow cytometry was used to evaluate sperm viability, mitochondrial membrane potential and DNA fragmentation. Intracellular levels of ATP and O consumption rate were also determined. Specific red-light patterns were found to modify kinetics parameters (patterns: 4, 2-2-2, 3-3-3, 4-4-4, 5-1-5, and 5-5-5 min), the structure of motile sperm subpopulations (patterns: 2, 2-2-2, 3-3-3, and 4-1-4 min), mitochondrial membrane potential (patterns: 4, 3-3-3, 4-4-4, 5-1-5, 5-5-5, 15-5-15, and 15-15-15 min), intracellular ATP levels and the rate of O consumption (pattern: 4 min), without affecting sperm viability or DNA integrity. Since the increase in some kinematic parameters was concomitant with that of mitochondrial activity, intracellular ATP levels and O consumption rate, we suggest that the positive effect of light-irradiation on sperm motility is related to its impact upon mitochondrial activity. In conclusion, this study shows that red LED light stimulates motility and mitochondrial activity of horse sperm. Additional research is needed to address the impact of red-light irradiation on fertilizing ability and the mechanisms through which light exerts its effects.
此前在其他哺乳动物物种上开展的研究表明，用红光刺激精液可提高精子活力、线粒体活性和受精能力。本研究旨在确定使用波长为620 - 630 nm的发光二极管（LED）进行红光刺激是否会影响马精子的活力、活动亚群的结构、精子活力、线粒体活性、细胞内ATP水平、耗氧率以及DNA完整性。为此，从9匹不同的成年种马采集了9份精液样本。采集后，精液用肯尼稀释液稀释，进行分析，调整其浓度，最后用红光刺激。在所有情况下，精液被包装在0.5 mL的透明细管中，随机分为对照组和19种光刺激处理组；6种为单次红光照射，另外13种涉及有照射和黑暗间隔（亮 - 暗 - 亮）的照射。照射后，使用计算机辅助精液分析系统（CASA）评估精子活力。采用流式细胞术评估精子活力、线粒体膜电位和DNA片段化。还测定了细胞内ATP水平和耗氧率。发现特定的红光模式可改变动力学参数（模式：4、2 - 2 - 2、3 - 3 - 3、4 - 4 - 4、5 - 1 - 5和5 - 5 - 5分钟）、活动精子亚群的结构（模式：2、2 - 2 - 2、3 - 3 - 3和4 - 1 - 4分钟）、线粒体膜电位（模式：4、3 - 3 - 3、4 - 4 - 4、5 - 1 - 5、5 - 5 - 5、15 - 5 - 15和15 - 15 - 15分钟）、细胞内ATP水平和耗氧率（模式：4分钟），而不影响精子活力或DNA完整性。由于一些运动学参数的增加与线粒体活性、细胞内ATP水平和耗氧率的增加同时出现，我们认为光照射对精子活力的积极作用与其对线粒体活性的影响有关。总之，本研究表明红色LED光可刺激马精子的活力和线粒体活性。需要进一步研究来探讨红光照射对受精能力的影响以及光发挥作用的机制。
