■氧化应激是指氧化剂和抗氧化剂活性与活性氧积累之间的不平衡,会对动物健康产生有害影响。氧化应激状态的年度波动可能发生,在某些时间段内增加疾病易感性。然而,缺乏对亚洲象氧化应激相关因素的充分理解,以及如何减轻负面后果。
■这项研究测量了六种血清氧化应激标志物[活性氧(ROS),丙二醛(MDA),8-羟基脱氧鸟苷(8-OHdG),白蛋白,谷胱甘肽过氧化物酶(GPx),和过氧化氢酶]和两个压力标记[血清皮质醇和粪便糖皮质激素代谢产物(fGCM)]在12个月内,在泰国的23头圈养的亚洲象中检查与年龄和季节的关系。
■观察到季节性变化,夏季有几种标记物表现出明显更高的浓度(ROS,MDA,8-OHdG,白蛋白)和雨季/冬季的较低值(MDA,8-OHdG,白蛋白,过氧化氢酶)。相比之下,GPx是雨季最高的唯一标记。对于应力标记,雨季FGCM浓度较高,这与早期研究显示冬季(旅游季节)活动更多形成鲜明对比。温度-湿度指数与ROS呈正相关,GPx,和fGCM,而与血清白蛋白呈负相关。大象内皮型疱疹病毒(EEHV)脱落事件与较高浓度的ROS和MDA有关。8-OHdG与EEHV脱落的PCR阈值周期(Ct)呈中度负相关,表明DNA损伤可能与大象的EEHV脱落有关。
■结果显示,年龄和季节对几种氧化应激标志物有显著影响,表明在研究设计和数据解释中应考虑这些因素。与环境变化有关的氧化应激条件也可能存在生理适应,这可能会影响健康结果。
UNASSIGNED: Oxidative stress refers to an imbalance between oxidant and antioxidant activity and accumulation of reactive oxygen species, which can have detrimental effects on animal health. Annual fluctuations in oxidative stress status can occur, increasing disease susceptibility during certain time periods. However, a full understanding of factors related to oxidative stress in Asian elephants and how to mitigate the negative consequences is lacking.
UNASSIGNED: This study measured six serum oxidative stress markers [reactive oxygen species (ROS), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), albumin, glutathione peroxidase (GPx), and catalase] and two stress markers [serum cortisol and fecal glucocorticoid metabolites (fGCM)] in 23 captive Asian elephants in Thailand over a 12 months period to examine relationships with age and season.
UNASSIGNED: Seasonal variations were observed, with several markers exhibiting significantly higher concentrations in the summer (ROS, MDA, 8-OHdG, albumin) and lower values during the rainy/winter seasons (MDA, 8-OHdG, albumin, catalase). By contrast, GPx was the only marker to be highest during the rainy season. For the stress markers, higher fGCM concentrations were noted during the rainy season, which contrasts with earlier studies showing more activity in the winter (tourist season). Positive correlations were found between the temperature-humidity index and ROS, GPx, and fGCM, while a negative correlation was observed with serum albumin. Elephant endotheliotropic herpesvirus (EEHV) shedding events were associated with higher concentrations of ROS and MDA. A moderate negative correlation was observed between 8-OHdG and the PCR threshold cycle of EEHV shedding (Ct), indicating DNA damage may be involved in EEHV shedding in elephants.
UNASSIGNED: Results revealed significant age and seasonal effects on several oxidative stress markers, indicating those factors should be considered in study design and data interpretation. There also may be physiological adaptations in oxidative stress conditions in relation to environmental changes that could impact health outcomes.