Reactive oxygen species (ROS) are the end-products of physiologic functions in health. Oxidative stress occurs when endogenous antioxidants are insufficient to neutralize ROS in the system. As a result, ROS can damage DNA, RNA, proteins, lipids, and cell organelles. To obtain accurate measurements of plasma oxidative stress, levels of both oxidants and antioxidants must be measured. This study validates a commercially available, semi-quantitative, photometric analytical system that measures systemic determinants of reactive oxygen metabolites (dROM) and plasma antioxidant capacity (PAC) in stored equine plasma. The objectives of this work were: 1) to validate a photometric analytical system to quantify dROM and PAC in equine plasma; and 2) to determine expected results for these tests in healthy adult horses. We hypothesized that this system would reliably and reproducibly assess dROM and PAC in equine plasma. We observed expected, dose-dependent increases in dROM generated by adding increasing concentrations of H₂O₂ or ascorbic acid to equine plasma to provide samples containing a known quantity of oxidants or antioxidants respectively. Mean dROM value in healthy horses was 103.3 $\pm 20.7$ U. Carr and mean PAC was 2881.0 $\pm$ 313.9 U. Cor. This system reliably and reproducibly quantified dROM and PAC in equine plasma samples.

活性氧（ROS）是健康生理功能的最终产物。当内源性抗氧化剂不足以中和系统中的ROS时，就会发生氧化应激。因此，ROS 会损害 DNA、RNA、蛋白质、脂质和细胞器。为了准确测量血浆氧化应激，必须测量氧化剂和抗氧化剂的水平。本研究验证了一种市售的半定量光度分析系统，该系统可测量储存的马血浆中活性氧代谢物 (dROM) 和血浆抗氧化能力 (PAC) 的系统决定因素。这项工作的目标是：1) 验证光度分析系统以量化马血浆中的 dROM 和 PAC；2) 确定健康成年马的这些测试的预期结果。我们假设该系统能够可靠且可重复地评估马血浆中的 dROM 和 PAC。我们观察到，通过向马血浆中添加浓度不断增加的 H ₂ O ₂或抗坏血酸以提供分别含有已知数量的氧化剂或抗氧化剂的样品，dROM 会出现预期的剂量依赖性增加。健康马的平均 dROM 值为 103.3$\pm 20.7$U. Carr 和平均 PAC 为 2881.0$\pm$313.9 美国科伦坡大学 该系统可靠且可重复地量化马血浆样本中的 dROM 和 PAC。