Journal of Applied Physiology, Vol 43, Issue 2 271-275, Copyright © 1977 by American Physiological Society
Changes in airway mast cells and histamine caused by antigen aerosol in allergic dogs
W. M. Gold, G. L. Meyers, D. S. Dain, R. L. Miller and H. R. Bourne
We studied the effect of inhaled specific antigen on airflow resistance,
histamine concentration, and mast cell numbers in airway tissues in
allergic dogs. In each of six allergic dogs with open chests, inhalation of
specific antigen aerosol (Ascaris suum) increased airflow resistance from
0.30+/-0.40 (mean+/-SE) to 2.8+/-0.41 cmH2O/1 per s (P less than 0.05);
decreased mast cell number from 38.6+/-3.2 to 24.3+/-4.5 mast cells/mm2 (P
less than 0.05); decreased histamine (per mg airway tissue) from 5.3+/-0.4
to 3.5+/-0.2 ng (P less than 0.05) in lobar bronchi 5-7 mm in diam; and
released histamine into the blood perfusing the lung, control arterial
plasma histamine; 2.8+/-0.64 ng/ml; antigen: 154+/-1.7 ng/ml (P less than
0.005). Specific antigen caused no significant changes in mast cells or
histamine in bronchi 1-2 mm in diam. Control aerosols of nonspecific
antigen or methacholine did not change levels of mast cells or histamine in
airway tissues. These results suggest that experimental canine asthma
involves local airway reactions with degranulation of mast cells and
histamine release, as well as vagally mediated reflex bronchoconstriction.
