Induction and down-regulation of conjunctival type-I hypersensitivity reactions in guinea pigs sensitized topically with fluoresceinyl ovalbumin.

Abstract

Type-I hypersensitivity reactions were induced in guinea pigs by repeated topical/conjunctival application of fluoresceinyl ovalbumin (FL-OA). The ocular reactivity in early responding animals was maximal between 16 and 25 days and decreased exponentially thereafter. Desensitized eyes responded minimally to compound 48/80 but maximally to histamine. Unilateral sensitization and challenge with FL-OA produced desensitization of the immunized eye, but the reactivity of the contralateral eye persisted. A significant reduction in conjunctival stained mast cells was found in repeatedly challenged eyes. The desensitization therefore was due to a loss of reactive mast cells. Systemic infection with Ascaris suum, after repeated topical challenge with FL-OA had led to desensitization, produced a reappearance of type-I hypersensitivity reactions toward both FL-OA and ascarid antigens.

• Authors: M Khatami, J J Donnelly, J H Rockey
• Journal: Ophthalmic research (Ophthalmic Res) Vol. 17 Issue 3 Pg. 139-47 ( 1985) ISSN: 0030-3747 [Print] Switzerland
• PMID: 4011127 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• fluorescein-ovalbumin
• p-Methoxy-N-methylphenethylamine
• Histamine
• Ovalbumin

Topics

• Administration, Topical
• Animals
• Ascariasis (immunology)
• Conjunctival Diseases (immunology, pathology)
• Desensitization, Immunologic
• Enzyme-Linked Immunosorbent Assay
• Female
• Guinea Pigs
• Histamine
• Hypersensitivity (immunology, pathology)
• Immunization
• Mast Cells (pathology)
• Ovalbumin (analogs & derivatives, immunology)
• p-Methoxy-N-methylphenethylamine