Acute effect of cigarette smoke and nicotine on airway blood flow and airflow in healthy smokers

Cigarette smoke contains irritants and vasoactive substances. We wanted to determine the effect of smoking a cigarette and of nasally or orally inhaled nicotine on airway blood flow (Q_aw) and airflow in smokers. In ten healthy current smokers, Q_aw, FEV₁, and FEF _25-75 were measured before and at 5, 30, and 180 min after smoking a cigarette. The effects of systemic nicotine using a nicotine nasal spray and local nicotine using a nicotine inhaler were also studied. Mean (± SE) Q_aw increased by 81% ± 16% (p = 0.03) 5 min after smoking a cigarette and was no longer different from baseline at 30 and 180 min. Nicotine nasal spray and nicotine oral inhaler had no effect on Q_aw. FEV ₁ and FEF_25-75 remained unchanged after smoking a cigarette and after local or systemic nicotine administration. Smoking a cigarette is followed by a transient increase in airway blood flow but no changes in airflow. Nicotine, at the rate and dose provided by the nasal spray (systemic action) and oral inhaler (local and systemic action), does not appear to be involved in the Q_aw change, suggesting a pharmacologic or nonspecific irritant effect of other cigarette smoke constituents.