Sotgia Salvatore, Taras Andrea, Zinellu Angelo, Cherchi Raffaele, Mangoni Arduino A, Carru Ciriaco, Bogliolo Luisa
Department of Biomedical Sciences, School of Medicine, University of Sassari, 07100 Sassari, Italy.
Agricultural Research Agency of Sardinia (AGRIS)-Research Service for Equine Production and Reproduction, 07014 Ozieri, Italy.
Antioxidants (Basel). 2020 Sep 13;9(9):855. doi: 10.3390/antiox9090855.
The dependence of a stallion's spermatozoa on oxidative phosphorylation for energy requirements results in an unconventional relationship between reactive oxygen species (ROS) production and fertility. In such a scenario, antioxidant activity must be finely controlled and not affect the essential functions of ROS. Some in vivo evidence suggests that the naturally occurring antioxidant ergothioneine (ERT) interferes with the critical roles of ROS/reactive nitrogen species (RNS) in pro-oxidant states but not in healthy tissues. The measurement of ERT in seminal plasma collected from 14 stallions (five Anglo-Arab, five Sella Italiano and four Thoroughbreds of which three are Arabian and one English) aged 16 ± 6 years (range 6-25 years) confirms that ERT is present at high concentrations in this biological fluid, between 16.80 and 971.48 µmol/L. Although the presence of high ERT concentrations in the seminal plasma of a stallion has long been known, its exact biological role is uncertain. This might be due to the peculiar antioxidant cycle of ERT, specifically its rapid recovery, which potentially masks concentration fluctuations and, therefore, the extent of its physiological effects. The measurement of the ERT precursor and redox metabolite hercynine (ERY) may overcome such issues, as ERY does not undergo regeneration processes. ERY was detectable and measurable in the seminal plasma of all stallions at a median concentration of 7.50 (IQR 15.26) nmol/L. The analysis of the association between the ERT and ERY, as well as with other established antioxidants such as glutathione and cysteine, suggests that ERT may play a major role in the antioxidant machinery of seminal plasma, and that ERY might serve as a new combined marker of oxidative stress and semen quality.
种马精子对氧化磷酸化产生能量的依赖性导致活性氧（ROS）生成与生育能力之间存在一种非常规关系。在这种情况下，抗氧化活性必须得到精细控制，且不能影响ROS的基本功能。一些体内证据表明，天然存在的抗氧化剂麦角硫因（ERT）会干扰ROS/活性氮物质（RNS）在促氧化状态下的关键作用，但在健康组织中不会。对14匹年龄在16±6岁（范围6 - 25岁）的种马（5匹盎格鲁阿拉伯马、5匹意大利赛拉马和4匹纯种马，其中3匹阿拉伯马和1匹英国马）采集的精浆中ERT的测量证实，这种生物体液中ERT浓度很高，在16.80至971.48µmol/L之间。尽管长期以来人们都知道种马精浆中存在高浓度的ERT，但其确切的生物学作用尚不确定。这可能是由于ERT独特的抗氧化循环，特别是其快速恢复，这可能掩盖了浓度波动以及其生理效应的程度。ERT前体和氧化还原代谢物组氨酸（ERY）的测量可能会克服这些问题，因为ERY不会经历再生过程。在所有种马的精浆中都可检测到并测量到ERY，中位浓度为7.50（IQR 15.26）nmol/L。对ERT与ERY之间以及与其他已确定的抗氧化剂如谷胱甘肽和半胱氨酸之间关联的分析表明，ERT可能在精浆的抗氧化机制中起主要作用，并且ERY可能作为氧化应激和精液质量的新综合标志物。
