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Allergen, bradykinin, and capsaicin increase outward but not inward macromolecular permeability of guinea‐pig tracheobronchial mucosa
Author(s) -
ERJEFÄLT I.,
PERSSON C. G. A.
Publication year - 1991
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.1991.tb00833.x
Subject(s) - bradykinin , carbachol , chemistry , ovalbumin , lamina propria , capsaicin , guinea pig , vascular permeability , extravasation , lumen (anatomy) , histamine , immunology , medicine , pathology , epithelium , antigen , biochemistry , receptor
Summary When inflammatory stimuli are applied on the airway mucosa, plasma is promptly extravasated from the subepithelial microvessels. The plasma exudate distributes in the lamina propria and much of it is soon transmitted across the epithelial lining. The rapid luminal entry of large plasma solutes must reflect a dramatic change in mucosal permeability. Previously it has been thought that such a perviousness of the mucosal barrier would be bidirectional in nature. This study in anaesthetized guinea‐pigs examines whether absorption across the mucosa is increased (above control) during, and immediately after, the plasma exudation process. An oral catheter, introduced into the tracheal lumen, was used to superfuse the lower airways with 0.04 ml of a solution containing the absorption tracer 131 I‐albumin and a selected dose of a provocating agent: allergen, 3 pmol (ovalbumin in IgE‐sensitized animals); bradykinin. 5 nmol; capsaicin, 0.4 nmol; or carbachol, 8 nmol. The superfusate had a desired distribution on the tracheobronchial mucosa so that specific airway and not bronchoalveolar exudation: absorption ratios could be determined. In separate experiments it was confirmed that the present provocations, except carbachol ( P > 0.05), moved significant amounts of plasma into the airway lumen ( P < 0.001). This was distinctly an increase in the outward mucosal permeability because the absorption of luminal 131 I‐albumin into circulating plasma was not significantly different from control with any of the provocations ( P > 0.05). The present data support our notion that unfiltered plasma exudates can operate on the mucosal surface, in first‐line defence reactions, without compromising the integrity of the epithelial lining as a barrier to luminal material.