Dale Ola, Bergum Hallgeir, Lund Terje, Nilsen Turid, Aadahl Petter, Stenseth Roar
Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Free Radic Res. 2003 Aug;37(8):815-21. doi: 10.1080/1071576031000107353.
Oxidative stress may initiate lipid peroxidation that generates ethane. Ethane, at low concentrations, is eliminated by pulmonary exhalation. Previous methods have not allowed frequent sampling, thus ethane kinetics has not been studied in man. A validated method over the range 3.8-100,000 ppb with a limit of quantitation of 3.8 ppb (CV 9.3%) based on cryofocusing technique of a 60 ml breath sample allowed frequent sampling. Due to a rapid analytical procedure batches of more than 100 samples may be analyzed. In human volunteers (24-55 years) uptake was studied for up to 23 min (n = 9), elimination was studied for 210 min (n = 9). Ethane was inhaled (concentrations varied from 16 to 29 ppm (parts per million)) through a non-rebreathing system; sampling was performed with short intervals from the expiratory limb. Samples were also drawn from the inhalatory limb. Ninety-five percent of steady state (inspired) concentration was reached within 1.75 min. Five percent of the initially inhaled concentrations was found in exhaled air 1.5 min after termination of inhalation. A terminal mean half life of 31 min for ethane was also observed. The data indicate that frequent sampling will be necessary to capture relevant changes in breath ethane.
氧化应激可能引发脂质过氧化反应，进而产生乙烷。低浓度的乙烷可通过肺部呼气排出体外。以往的方法无法实现频繁采样，因此尚未对人体的乙烷动力学进行研究。一种基于60毫升呼吸样本冷冻聚焦技术的经过验证的方法，其测量范围为3.8 - 100,000 ppb，定量限为3.8 ppb（变异系数9.3%），该方法允许进行频繁采样。由于分析过程快速，一批超过100个样本均可进行分析。在年龄为24 - 55岁的人类志愿者中，对乙烷的摄取进行了长达23分钟的研究（n = 9），对其消除过程进行了210分钟的研究（n = 9）。通过非重复呼吸系统吸入乙烷（浓度范围为16至29 ppm（百万分之一））；从呼气支路以短时间间隔进行采样。同时也从吸气支路采集样本。在1.75分钟内达到了稳态（吸入）浓度的95%。在吸入终止1.5分钟后，呼出气体中发现了初始吸入浓度的5%。还观察到乙烷的终末平均半衰期为31分钟。数据表明，有必要进行频繁采样以捕捉呼出乙烷的相关变化。
