The role of histamine H(1) receptors in late-phase reaction of allergic conjunctivitis.

The role of histamine H(1) receptors in the late-phase reaction of allergic conjunctivitis was studied using histamine H(1) receptor-deficient mice. To clarify the eosinophil infiltration, which is a reliable indicator of late-phase reaction, eosinophil peroxidase activity in the conjunctiva was measured. Mice were actively immunized with ovalbumin, and conjunctivitis was induced by topical instillation of ovalbumin.