Effect of allergic bronchoconstriction on airways epithelial permeability to large polar solutes in the guinea pig.

The effect of allergic bronchoconstriction on the permeability of the airway mucosa to large hydrophilic polar solutes was investigated in the guinea pig. After specific antigen (ovalbumin) challenge, there was a significant increase in the plasma levels of horseradish peroxidase (HRP) (molecular weight, approximately 40,000 daltons), 3H-dextran (approximately 10,000 daltons), and 14C-mannitol (approximately 182 daltons) compared with that in control animals aerosol-challenged with a nonspecific protein, lactoglobulin. The morphologic correlates of this enhanced transepithelial permeability after ovalbumin challenge appeared to be (1) increased HRP penetration of the epithelial tight junctions (p less than 0.001), and (2) increased mucus discharge from surface lining goblet cells. We conclude that antigen-induced bronchoconstriction leads to an increase in tracheobronchial permeability to macromolecules, and this effect is likely to be mediated by an increased paracellular as well as transcellular vesicular movement of large polar solutes across the airway epithelial barrier.