AJP - Lung Cellular and Molecular Physiology, Vol 257, Issue 6 366-L372, Copyright © 1989 by American Physiological Society
Local mediator release after antigen challenge of a bronchial segment in allergic dogs
T. F. Reiss, I. Rubinstein, D. L. Emery, W. M. Gold and H. A. Boushey Jr
Department of Medicine, University of California, San Francisco 94143-0130.
To investigate the local intraluminal bronchial response to an antigenic
stimulus, we developed a bronchoscopic double-balloon system to challenge
and lavage a segment of the left main-stem bronchus. We studied whether
fluid from above or below the occlusion balloons leaked into the bronchial
segment. Lavage was performed before and after placement of red and blue
pigments proximal and distal to the inflated balloons, respectively, and
the recovered lavage fluid was analyzed visually and spectrophotometrically
in three experiments. There was no evidence for pigment leakage into the
segment. In six anesthetized ragweed-allergic dogs, local ragweed antigen
challenges were performed. After balloon inflation in the left main-stem
bronchus, we performed two baseline lavages of the interballoon segment,
introduced a ragweed antigen solution, and performed two postchallenge
lavages. The recovered fluid was analyzed for the concentrations of
prostaglandin D2 (PGD2; radioimmunoassay) and histamine (fluorometric
technique) and for total and differential cell counts. Antigen challenge
was associated with a significant increase in PGD2 concentration in the
recovered fluid, rising from a median of 178 pg/ml (range, 157-647) before
to 919 pg/ml (range, 149-2,452) after challenge. Median histamine
concentrations were 3.1 ng/ml (range, 1-5.4 ng/ml) before and 5.6 ng/ml
(range, 1-16.2) after challenge (P = not significant). In four dogs, a
control challenge with the antigen vehicle alone showed no change in either
mediator. Changes in cell counts after challenge were
inconsistent.(ABSTRACT TRUNCATED AT 250 WORDS)
