Habib M P, Clements N C, Garewal H S
Section of Pulmonary Medicine, Veterans Affairs Medical Center, Tucson, Arizona 85723, USA.
Am J Respir Crit Care Med. 1995 May;151(5):1368-72. doi: 10.1164/ajrccm.151.5.7735586.
The time course of exhaled ethane gas was determined in the alveolar expirate of healthy, fasting smokers and nonsmokers after smoking a cigarette. Baseline ethane was measured by gas chromatography and corrected for background ethane after a 2-min washout using purified air. Ethane was measured immediately after smoking and hourly thereafter. Ethane was highest immediately after smoking, reflecting ethane in cigarette smoke. An exponential decline of ethane in smokers returned ethane to baseline within 3 h. Ethane in nonsmokers also peaked immediately after smoking but returned to baseline by 1 h. Ethane from smokers, measured 3 h after the last cigarette, was compared with ethane from healthy ex-smokers and nonsmokers. Mean (+/- SEM) baseline ethane in smokers was 2.90 +/- 0.52 pmol/min/kg, 1.55 +/- 0.36 pmol/min/kg in ex-smokers and 1.11 +/- 0.26 pmol/min/kg in nonsmokers (p < 0.05). Ethane in two smokers measured before and after a week of oral beta carotene supplementation (60 mg/d) fell by 80 and 35%. We conclude that cigarette smokers have increased baseline ethane in exhaled breath compared with non-smokers. Trials with antioxidant agents are warranted to assess their ability to reduce expired ethane levels.
在健康、空腹的吸烟者和不吸烟者吸完一支烟后，测定其肺泡呼出气中乙烷气体的时间进程。通过气相色谱法测量基线乙烷，并在使用净化空气冲洗2分钟后对背景乙烷进行校正。吸烟后立即测量乙烷，此后每小时测量一次。吸烟后乙烷立即达到最高值，反映出香烟烟雾中的乙烷。吸烟者体内乙烷呈指数下降，3小时内恢复至基线水平。不吸烟者体内乙烷在吸烟后也立即达到峰值，但1小时后恢复至基线水平。将最后一支烟吸完3小时后吸烟者呼出的乙烷与健康戒烟者和不吸烟者呼出的乙烷进行比较。吸烟者的平均（±标准误）基线乙烷为2.90±0.52 pmol/分钟/千克，戒烟者为1.55±0.36 pmol/分钟/千克，不吸烟者为1.11±0.26 pmol/分钟/千克（p<0.05）。两名吸烟者在口服β-胡萝卜素补充剂（60毫克/天）一周前后测量的乙烷分别下降了80%和35%。我们得出结论，与不吸烟者相比，吸烟者呼出气体中的基线乙烷增加。有必要进行抗氧化剂试验，以评估其降低呼出乙烷水平的能力。
