Journal of Applied Physiology, Vol 52, Issue 4 1071-1076, Copyright © 1982 by American Physiological Society
Effects of acute and chronic exposure to nicotine aerosol on bronchial reactivity to inhaled methacholine
T. W. Wallis, W. R. Rogers and W. G. Johanson Jr
Normal baboons, like humans, demonstrate a wide range of bronchial
reactivity to inhaled methacholine. Cigarette-smoking baboons demonstrate
reduced bronchial reactivity to inhaled methacholine compared with
sham-smoking controls after 6 pack-yr of smoking. To evaluate the role of
nicotine in this blunting of airway reactivity, we studied the effects of
both acute and chronic nicotine inhalation on reactivity to methacholine in
baboons. Inhalation of 2 mg of nicotine had no acute effect on lung
function but blunted bronchial reactivity in highly reactive animals. This
effect was not diminished after daily inhalation of nicotine for 90 days.
Marked interindividual differences in bronchial reactivity to methacholine
were not abolished by propranolol, suggesting that factors other than
beta-adrenergic tone account for this intersubject variability.
