Asadpour Reza, Taravat Morteza, Rahbar Maryam, Khoshniyat Mohammadrasoul, Hamidian Gholamreza
Department of Clinical Science, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.
Research Center of Iranian Nahadehaye Dami Jahed (NDJ), Karaj, Iran.
Basic Clin Androl. 2021 Aug 5;31(1):20. doi: 10.1186/s12610-021-00137-5.
Asthenozoospermia is a usual male infertility factor, characterized by decreased semen quality. It has been revealed that antioxidants improve sperm function, enhance endogenous antioxidant activities, and protect spermatozoa against oxidative damage during cryopreservation. This aimed to evaluate the effects of vitamin D on sperm kinematics and apoptosis in the semen of bulls with normozoospermia and asthenozoospermia after the freeze-thaw process. For this purpose, 32 semen samples of four Holstein bulls (normozoospermic, progressive motility > 70 %) and 32 semen samples of four bull (asthenozoospermic progressive motility < 40 %) were collected and pooled separately (normozoospermic and asthenozoospermic). Samples were then diluted into four equal aliquots of extender containing different vitamin D concentrations (0, 5, 10, and 50 ng/mL) and aspirated into a 0.5 mL straw.
The percentages of sperm progressive motility and viability were significantly higher (P < 0.05) in 50 ng/mL of vitamin D in normozoospermic group. Sperm kinematics parameters including curvilinear velocity (VCL), straight-line velocity (VSL), and average path velocity (VAP) were significantly higher in the high dose (50 ng/mL) vitamin D-treated group compared to the low dose vitamin D-treated group (5ng/mL) in normozoospermic bull semen samples. The supplementation of the semen extender with different concentrations of vitamin D could not increase the rate of acrosome integrity in normozoospermic bulls compared to the control group (P < 0.05). In the asthenozoospermic group, 10 ng/mL vitamin D-treated group could increase the rate of plasma membrane integrity compared to 5 ng/mL vitamin D-treated group (P < 0.05). The percentages of early-apoptosis (P = 0.049) and late-apoptosis (P = 0.005) were significantly higher in the asthenozoospermic than the normozoospermic group.
The present study revealed that a high dose (50 ng/mL) of vitamin D protected normozoospermic bulls' sperms from the freezing procedure and lead to higher quality of frozen-thawed bull sperm.
弱精子症是男性不育的常见因素，其特征是精液质量下降。研究表明，抗氧化剂可改善精子功能，增强内源性抗氧化活性，并在冷冻保存过程中保护精子免受氧化损伤。本研究旨在评估维生素D对正常精子症和弱精子症公牛精液在冻融过程后精子运动学和细胞凋亡的影响。为此，分别收集了四头荷斯坦公牛的32份精液样本（正常精子症，前向运动率>70%）和四头公牛的32份精液样本（弱精子症，前向运动率<40%），并分别合并（正常精子症和弱精子症）。然后将样本稀释成四份等份的含有不同维生素D浓度（0、5、10和50 ng/mL）的稀释液，并吸入0.5 mL细管中。
正常精子症组中，50 ng/mL维生素D组的精子前向运动率和活力百分比显著更高（P<0.05）。在正常精子症公牛精液样本中，与低剂量维生素D处理组（5 ng/mL）相比，高剂量（50 ng/mL）维生素D处理组的精子运动学参数，包括曲线速度（VCL）、直线速度（VSL）和平均路径速度（VAP）显著更高。与对照组相比，在正常精子症公牛中添加不同浓度的维生素D并不能提高顶体完整性率（P<0.05）。在弱精子症组中，10 ng/mL维生素D处理组与5 ng/mL维生素D处理组相比，可提高质膜完整性率（P<0.05）。弱精子症组的早期凋亡（P = 0.049）和晚期凋亡（P = 0.005）百分比显著高于正常精子症组。
本研究表明，高剂量（50 ng/mL）的维生素D可保护正常精子症公牛的精子免受冷冻过程的影响，并使冻融后的公牛精子质量更高。
