Housley D G, Mudway I, Kelly F J, Eccles R, Richards R J
School of Molecular and Medical Biosciences, University of Wales, College of Cardiff, England.
Int J Biochem Cell Biol. 1995 Nov;27(11):1153-9. doi: 10.1016/1357-2725(95)00089-8.
Ozone, a strong oxidant present in summer smog, is thought to primarily react with antioxidant molecules found in the epithelial lining fluid of the respiratory tract. In humans, as much as 40% of inhaled ozone can be removed in the nasal cavity where the major extracellular antioxidant has been identified as uric acid. The present study was undertaken to examine urate/oxidant interactions in human nasal lavage fluid following in vitro exposure to ozone at concentrations relevant to the U.K. Lavage fluid was collected from 8 volunteers using a modified Foley catheter which permits prolonged contact of isotonic saline with the anterior nasal cavity. Nasal lavage samples in multiwell plates were exposed to ozone at concentrations of 50, 100 and 250 ppb. Samples were removed at intervals from 15 to 240 min following exposure and assayed for uric acid depletion. Uric acid concentrations in the nasal lavage were found to fall from 8.52 (time zero) to 3.99 microM, 0.05 and 0.07 microM after 240 min at 50, 100 and 250 ppb ozone respectively. At a non-environmentally relevant ozone concentration of 1000 ppb, uric acid was completely depleted after 60 min. Regression analysis showed a linear correlation between rate of loss of urate and ozone concentration (R2 = 0.97). A novel, non-invasive technique is described to investigate antioxidant compromise and its importance in individual subjects. We conclude that uric acid in nasal lavage samples is scavenged by ozone in a dose and time dependent manner.
臭氧是夏季烟雾中存在的一种强氧化剂，被认为主要与呼吸道上皮衬液中的抗氧化分子发生反应。在人类中，吸入的臭氧多达40%可在鼻腔中被清除，鼻腔中的主要细胞外抗氧化剂已被确定为尿酸。本研究旨在检测体外暴露于与英国相关浓度的臭氧后，人鼻灌洗液中尿酸盐/氧化剂的相互作用。使用改良的福勒导管从8名志愿者收集灌洗液，该导管可使等渗盐水与前鼻腔长时间接触。将多孔板中的鼻灌洗样本暴露于浓度为50、100和250 ppb的臭氧中。暴露后每隔15至240分钟取出样本，检测尿酸消耗情况。发现鼻灌洗液中的尿酸浓度在臭氧浓度为50、100和250 ppb时，240分钟后分别从8.52（零时）降至3.99微摩尔、0.05微摩尔和0.07微摩尔。在与环境无关的1000 ppb臭氧浓度下，60分钟后尿酸完全耗尽。回归分析表明尿酸盐损失率与臭氧浓度之间呈线性相关（R2 = 0.97）。描述了一种新的非侵入性技术，用于研究抗氧化剂的损害及其在个体受试者中的重要性。我们得出结论，鼻灌洗样本中的尿酸被臭氧以剂量和时间依赖性方式清除。
