Journal of Applied Physiology, Vol 65, Issue 3 1119-1124, Copyright © 1988 by American Physiological Society
Acute transient SO2-induced airway hyperreactivity: effects of nedocromil sodium
D. M. Jackson and R. P. Eady
Fisons Public Limited Company-Pharmaceutical Division, Loughborough, Leicestershire, United Kingdom.
The effect of nedocromil sodium given as an aerosol on the immediate lung
hyperreactivity and lung inflammation caused by a 2-h exposure to 400 ppm
SO2 has been studied in dogs. Exposure to SO2 caused an immediate increase
in bronchial responsiveness to histamine aerosol that lasted for
approximately 2 h. The total number of cells recovered by bronchial lavage
increased postexposure. Initially this increase was caused by epithelial
cells (0.25 and 1 h) and later by neutrophils (1, 2, 3, and 4 h). There was
no significant change in the numbers of lymphocytes, macrophages,
eosinophils, goblet cells, or mast cells in the lavages. Nedocromil sodium
(approximately 8 mg) given as a nebulized aerosol before and after SO2
exposure prevented the increase in lung reactivity and attenuated the
increase in the total number of cells (epithelial cells and neutrophils) in
the lung lavages for the 4 h after exposure. Nedocromil sodium did not
affect the reactivity of normal dogs to histamine aerosol. Nedocromil
sodium appears to act as an anti-inflammatory agent in this model of lung
inflammation, preventing an increase in lung reactivity and reducing cell
infiltration. The mechanism of action of nedocromil sodium in this model is
unknown.
