Hartell M G, Borzone G, Clanton T L, Berliner L J
Department of Chemistry, Ohio State University, Columbus.
Free Radic Biol Med. 1994 Nov;17(5):467-72. doi: 10.1016/0891-5849(94)90173-2.
Previous work has suggested that a free radical mechanism is involved in some types of muscle fatigue and that there can be free radicals released extracellularly. Because muscle fatigue may be an important factor in respiratory failure, the authors tested the hypothesis that increased concentrations of free radicals could be detected in the blood of animals undergoing severe resistive loading to respiratory failure. An ex vivo spin trapping technique with alpha-phenyl-N-tert-butylnitrone (PBN) was used to investigate the possible formation of free radicals in systemic blood samples by electron spin resonance (ESR) spectrometry. After 2.5-3 h of severe inspiratory resistive loading with 70% supplemental inspired oxygen, free radical levels in the form of PBN-adducts were found to rise significantly over the control group breathing room air and the control group breathing 70% oxygen (p < 0.05, N = 8). There were no significant differences between control groups breathing room air and control groups breathing 70% oxygen. This study presents direct evidence that free radicals are produced ex vivo and that they can be detected in the systemic circulation due to excessive resistive loading of the respiratory muscles.
先前的研究表明，自由基机制与某些类型的肌肉疲劳有关，并且细胞外可释放自由基。由于肌肉疲劳可能是呼吸衰竭的一个重要因素，因此作者检验了这样一个假设：在经历严重抵抗性负荷直至呼吸衰竭的动物血液中，可以检测到自由基浓度升高。采用α-苯基-N-叔丁基硝酮（PBN）的体外自旋捕获技术，通过电子自旋共振（ESR）光谱法研究全身血样中自由基的可能形成。在吸入70%补充氧气进行2.5 - 3小时的严重吸气抵抗性负荷后，发现以PBN加合物形式存在的自由基水平比呼吸室内空气的对照组和呼吸70%氧气的对照组显著升高（p < 0.05，N = 8）。呼吸室内空气的对照组和呼吸70%氧气的对照组之间没有显著差异。这项研究提供了直接证据，证明自由基在体外产生，并且由于呼吸肌的过度抵抗性负荷，它们可以在体循环中被检测到。
