Liu Heliang, Zhang Deliang, Zhao Baolu, Zhao Jinyuan
Research Center of Occupational Medicine, Peking University Third Hospital, Beijing 100083, People's Republic of China.
Free Radic Res. 2004 Dec;38(12):1281-7. doi: 10.1080/10715760400006940.
It is believed that reactive oxygen species (ROS) play a very important role in the pathogenesis of acute respiratory distress syndrome (ARDS), but the mechanism has not been so clear, owing to the absence of direct measurable (experimental) data. In majority of the medical studies on free radicals, the analysis of ROS has generally been done by the way of measuring their secondary and breakdown products. In our study, we used electron spin resonance (ESR), a sensitive and accurate technique to detect ROS directly and also used some other sensitive techniques including ultra-weak luminescence and chemical luminescence to identify the species and relative amount of ROS. Furthermore, superoxide dismutase (SOD) was pre-administrated in ARDS rats to verify the results from the above studies and explore the possibility of the clinical application of SOD in ARDS. The spectra of ESR showed that the concentration of ROS increased at 10 min and reached a summit at 30 min after injection of oleic acid (OA), then dropped gradually. The scavenging effects of different scavenging agents on ROS by the analysis of ultra-weak luminescence proved that superoxide anion was the main species of ROS in the development of OA-induced ARDS. Moreover, the results of quantified measure of superoxide anion by chemical luminescence also showed the accordant tendency exhibited in ESR measurement. The pre-treatment of SOD might distinctly inhibit the production of superoxide anion, obviously improve the blood gas status, lung wet/dry ratio and lung/body ratio in ARDS rats. It is suggested that ROS may play a key role in the initiation phase of ARDS, while superoxide anion may be a leading actor in this process and SOD could effectively protect rats from ARDS. These results may provide helpful information for the treatment and prevention of ARDS.
人们认为活性氧(ROS)在急性呼吸窘迫综合征(ARDS)的发病机制中起着非常重要的作用,但由于缺乏直接可测量的(实验)数据,其机制尚未完全明确。在大多数关于自由基的医学研究中,ROS的分析通常是通过测量其二级产物和分解产物来进行的。在我们的研究中,我们使用电子自旋共振(ESR)这一灵敏且准确的技术直接检测ROS,还使用了其他一些灵敏技术,包括超微弱发光和化学发光,以鉴定ROS的种类和相对含量。此外,在ARDS大鼠中预先给予超氧化物歧化酶(SOD),以验证上述研究结果,并探索SOD在ARDS临床应用的可能性。ESR光谱显示,注射油酸(OA)后10分钟时ROS浓度升高,30分钟时达到峰值,然后逐渐下降。通过超微弱发光分析不同清除剂对ROS的清除作用,证明超氧阴离子是OA诱导的ARDS发生过程中ROS的主要种类。此外,化学发光法定量测定超氧阴离子的结果也显示出与ESR测量一致的趋势。SOD预处理可能明显抑制超氧阴离子的产生,显著改善ARDS大鼠的血气状态、肺湿/干比和肺/体比。提示ROS可能在ARDS的起始阶段起关键作用,而超氧阴离子可能是这一过程中的主要参与者,SOD可有效保护大鼠免受ARDS侵害。这些结果可能为ARDS的治疗和预防提供有用信息。