AJP - Lung Cellular and Molecular Physiology, Vol 257, Issue 4 277-L283, Copyright © 1989 by American Physiological Society
Kinetics of cellular influx and histamine release in normal human bronchi
J. A. Cooper Jr, W. W. Merrill and M. G. Buck
Pulmonary Section, West Haven Veterans Administration Medical Center 06516.
Inhalation of certain substances can induce bronchial inflammation followed
by bronchoconstriction or bronchial hyperreactivity. We have developed a
model of airway inflammation and bronchoconstriction induced by an aqueous
extract of cotton bracts (CBE) in which the severity of flow rate reduction
correlates with the presence of bronchoalveolar neutrophils. In the current
study normal human volunteers underwent local bronchial instillation of
CBE. Bronchial lavage histamine concentrations and cellular populations
were determined at time intervals after local challenge. In addition,
bronchial biopsies were obtained after CBE instillation, and the degree of
subepithelial inflammation was quantitated. We report that lavage of
bronchi locally exposed to CBE contains 1) greater histamine concentrations
4 min after challenge compared with lavage from saline-challenged bronchi
and 2) concentrations of eosinophils and macrophages that are greater than
control lavage 8 min after exposure. Bronchial biopsies taken after CBE
instillation also demonstrated a variable degree of subepithelial
granulocyte infiltration that correlated with the global
bronchoconstricting response to CBE assessed on a separate day. These
studies suggest that inflammation can develop rapidly in normal human
bronchi and may precede significant flow rate reductions by greater than 1
h.
