Gerber C E, Bruchelt G, Stegmann H, Schweinsberg F, Speer C P
Department of Neonatology, Children's University Hospital, Rümelinstr. 23, Tübingen, D-72070, Germany.
Biochem Biophys Res Commun. 1999 Apr 2;257(1):218-22. doi: 10.1006/bbrc.1999.0435.
Chronic lung disease (CLD) is a major cause of long term morbidity in preterm infants. Reactive oxygen species (ROS) play an important role in the pathogenesis of CLD. We show that a high percentage (63 to 83%) of the investigated bronchoalveolar secretions (BAS) of neonates contain bleomycin-detectable free iron concentrations (0. 04-0.124 nmol/micrograms SC, median range). Beside the presence of redox-active iron several iron-binding proteins like transferrin, ferritin and lactoferrin were determined in BAS. Comparison of protein distribution within the first three days of life showed slight differences between the group of preterm infants who developed CLD and the neonates who recovered from RDS. Because of the existence of free iron we suggest a higher risk of hydroxyl radical formation in the alveolar space. In an artificial system with addition of iron and hydrogen peroxide we were able to demonstrate OH-radical production in BAS by electron paramagnetic resonance (EPR). OH-radical formation by H2O2 and iron in buffer solution was slightly enhanced in the presence of BAS, indicating the absence of OH-radical-scavengers in BAS.
慢性肺部疾病（CLD）是早产儿长期发病的主要原因。活性氧（ROS）在CLD的发病机制中起重要作用。我们发现，所研究的新生儿支气管肺泡灌洗液（BAS）中有很高比例（63%至83%）含有可检测到的博来霉素游离铁浓度（0.04 - 0.124纳摩尔/微克表面活性物质，中位数范围）。除了存在具有氧化还原活性的铁之外，还在BAS中检测到了几种铁结合蛋白，如转铁蛋白、铁蛋白和乳铁蛋白。对出生后前三天内蛋白质分布的比较显示，患CLD的早产儿组与从呼吸窘迫综合征（RDS）中康复的新生儿组之间存在细微差异。由于游离铁的存在，我们认为肺泡腔中形成羟基自由基的风险更高。在添加了铁和过氧化氢的人工系统中，我们能够通过电子顺磁共振（EPR）证明BAS中产生了羟基自由基。在BAS存在的情况下，缓冲溶液中过氧化氢和铁形成羟基自由基的过程略有增强，这表明BAS中不存在羟基自由基清除剂。
