Biomarkers Of Oxidative Stress Study

现在，我们在另外两个氧化应激实验动物模型上的氧化应激测量中有了新的发现：90天的异丙苯过氧化氢皮肤暴露和小型猪的内毒素治疗。用新旧技术研究氧化损伤对血浆和尿液中过氧化脂质、总胆红素、丙二醛和异前列腺素浓度的时间和剂量效应。还测定了蛋白质氧化产物(蛋白质羰基、蛋氨酸亚磺酸氧化和酪氨酸氧化产物)和DNA氧化产物(链断裂、8-OHdG和M1G)。此外，还研究了两种暴露对血浆α-生育酚、辅酶Q(CoQ)、抗坏血酸、谷胱甘肽(GSH和GSSG)、尿酸和总抗氧化能力的时间和剂量依赖性影响，以确定不同伤害的氧化作用是否会导致血浆抗氧化剂水平的下降。 先前急性接触CCl4和臭氧发现，CCl4处理的大鼠血浆丙二醛和异前列腺素浓度(用GC/MS测量)和尿异前列腺素浓度(用免疫测定法测量)都以时间和剂量依赖的方式增加。所有其他产品不会被CCl4改变或仅显示高剂量和/或单一时间点效应。然而，在臭氧暴露模型中，血浆丙二醛和异前列腺素浓度(用GC/MS测量)没有改变，而尿液中异前列腺素浓度(用免疫测定法测量)增加。CCl4和臭氧对蛋白质氧化产物(蛋白质羰基、蛋氨酸亚硫基氧化、酪氨酸氧化产物)和DNA(链断裂、8-OHdG、M1G)的测定没有时间和剂量依赖关系。结论：血浆(GC/MS)和尿液(GC/MS)中自由基介导的脂质过氧化产物--丙二醛(MDA)和异前列腺素(Isoprostanes)浓度的测定有望成为氧化应激的一般生物标志物。在这三种暴露中看到的氧化应激生物标记物的模式将提供对标记物的特异性和敏感性的洞察，并将提供证据，证明给定的氧化产物可能是某种类型的氧化应激的标记物，而不是其他类型的氧化应激标记物。

We now have new findings from measurement of oxidative stress in two additional experimental animal models of oxidative stress: 90-day cumene hydroperoxde dermal exposure and LPS treatment of minipigs. The time and dose-dependent effects of these oxidative insults on plasma and urine concentrations of lipid hydroperoxides, TBARS, malondialdehyde (MDA) and isoprostanes were investigated with both old and new techniques. Measures of oxidative products of proteins (protein carbonyls, methionine sulfoxidation, and tyrosine oxidation products) and of DNA (strand breaks, 8-OHdG, and M1G) were carried out as well. In addition, the time- and dose-dependent effects of the two exposures on plasma levels of alpha-tocopherol, coenzyme Q (CoQ), ascorbic acid, glutathione (GSH and GSSG), uric acid and total antioxidant capacity were investigated to determine whether the oxidative effects of diverse insults would result in a decrease of plasma antioxidants. Previous acute exposure to CCl4 and ozone found that plasma concentrations of MDA and isoprostanes (measured by GC/MS) and urinary concentrations of isoprostanes (measured with an immunoassay) were increased in CCl4 treated rats in a time- and dose-dependent manner. All other products were not changed by CCl4 or showed only high-dose and/or single time point effects. In the ozone exposure model, however, plasma concentrations of MDA and isoprostanes (measured by GC/MS) were not changed whereas urinary concentrations of isoprostanes (measured with an immunoassay) were increased. Measures of oxidation products of proteins (protein carbonyls, methionine sulfoxidation, tyrosine oxidation products) and DNA (strand breaks, 8-OHdG, M1G) were not changed in a time-and dose-dependent manner by CCl4 and ozone. It is concluded that measurements of free radical mediated lipid peroxidation products - MDA and isoprostanes concentrations in plasma (by GC/MS) and urinary isoprostanes (by immunoassay or GC/MS) are promising candidates for general biomarkers of oxidative stress. The pattern of oxidative stress biomarkers seen in these three exposures will offer insight into the specificity and sensitivity of the markers and will provide evidence that a given product of oxidation may be a marker for some type of oxidative stress but not others.