Effect of histamine on nasal epithelial permeability to horseradish peroxidase in allergic guinea pigs.

The effect of histamine and antigen on the permeability of nasal mucosa to macromolecules in allergic guinea pigs was investigated with a histochemical technique using horseradish peroxidase (HRP). We found that the ratio of intercellular spaces penetrated by HRP to the total number of intercellular spaces of the nasal epithelium in nonallergic groups was increased by histamine challenge dose-dependently. The HRP reaction products in the intercellular spaces in allergic groups were significantly increased by challenge with histamine at 5.4 x 10(-4) mol/L and 5.4 x 10(-2) mol/L, in contrast to nonallergic groups. We conclude that histamine increases nasal mucosal permeability, and this effect is most likely mediated by a functional change in the epithelial tight junctions.