Acute inhalation of cigarette smoke increases lower respiratory tract nitric oxide concentrations

BACKGROUND Cigarette smoking is associated with a number of common pulmonary diseases including chronic airflow limitation and bronchial carcinoma. Lower respiratory tract (LRT) nitric oxide (NO) concentrations are reduced in habitual cigarette smokers between cigarettes, and although this finding has been implicated in the pathogenesis of smoking related disease, the underlying mechanisms are unclear. A study was undertaken to determine the nature and time course for changes in LRT NO concentrations following acute inhalation of cigarette smoke. METHODS Twenty four healthy habitual smokers were studied. The concentration of LRT NO in exhaled breath before, one and ten minutes after smoking a single cigarette was measured using chemiluminescence. RESULTS LRT NO concentrations increased in all subjects from a mean (SE) of 2.6 (0.27) to 4.8 (0.26) ppb (p