Armstrong K L, Cooper M F, Williams M T, Elsayed N M
Department of Respiratory Research, Walter Reed Army Institute of Research, Washington, DC 20307, USA.
Biochem Biophys Res Commun. 1998 Dec 9;253(1):114-8. doi: 10.1006/bbrc.1998.9762.
Exposure to high energy impulse noise (BLAST) caused by explosions, result in structural and functional damage to the hollow organs, especially to the respiratory and auditory systems. Lung damage includes alveolar wall rupture, edema and hemorrhage, and may be fatal. Previous observations at the molecular level using the rat model, suggested that secondary free radical-mediated oxidative stress occurs post exposure resulting in antioxidant depletion and hemoglobin (Hb) oxidation. This study examined whether a short period of pre-exposure supplementation with antioxidants would protect Hb from the effects of BLAST exposure. Six groups of male Sprague-Dawley rats (8/group) were gavaged with 800 IU vitamin E (VE) in 2 ml corn oil, 1000 mg vitamin C (VC) in 2 ml distilled water or 25 mg or (-lipoic acid (LA) in 2 ml corn oil for 3 days. Matched control groups were gavaged with the respective vehicles. On day 4, rats were deeply anesthetized and exposed to a simulated BLAST wave with an average peak pressure of 62 +/- 2 kPa. Rats were euthanized one hour post exposure and blood samples were obtained by cardiac puncture and analyzed using a hemoximeter. Post exposure oxygenation states (HbO2, O2 saturation, and O2 content) were markedly decreased, while reduced-Hb was increased. Supplementation with VE and LA reversed the trend and increased Hb oxygenation, but VC did not. This suggests that a brief dietary loading with pharmacological doses of VE or LA, but not VC shortly before BLAST exposure may be beneficial. Moreover, measurement of blood oxygenation may function as a simple semi-invasive biomarker of BLAST-induced injury applicable to humans.
爆炸产生的高能脉冲噪声（冲击波）会对中空器官造成结构和功能损伤，尤其是对呼吸系统和听觉系统。肺部损伤包括肺泡壁破裂、水肿和出血，可能会致命。此前利用大鼠模型在分子水平进行的观察表明，暴露后会发生继发性自由基介导的氧化应激，导致抗氧化剂耗竭和血红蛋白（Hb）氧化。本研究考察了短时间暴露前补充抗氧化剂是否能保护Hb免受冲击波暴露的影响。将六组雄性Sprague-Dawley大鼠（每组8只）分别用2 ml玉米油中的800 IU维生素E（VE）、2 ml蒸馏水中的1000 mg维生素C（VC）或2 ml玉米油中的25 mg α-硫辛酸（LA）灌胃3天。相应的对照组用各自的赋形剂灌胃。在第4天，将大鼠深度麻醉并暴露于平均峰值压力为62±2 kPa的模拟冲击波中。暴露1小时后对大鼠实施安乐死，通过心脏穿刺采集血样并用血氧计进行分析。暴露后氧合状态（HbO2、氧饱和度和氧含量）显著降低，而还原型Hb增加。补充VE和LA可逆转这一趋势并增加Hb氧合，但VC则不能。这表明在冲击波暴露前不久，短期给予药理剂量的VE或LA（而非VC）进行饮食负荷可能有益。此外，测量血液氧合可能作为一种适用于人类的冲击波诱导损伤的简单半侵入性生物标志物。
