title: The effect of the selective PAF antagonist WEB 2170 on PAF and antigen induced airway hyperresponsiveness and eosinophil infiltration.
abstract: Exposure of normal guinea pigs to an aerosol of PAF induced an increase in airway responsiveness to i.v. histamine, 24 h and 48 h post challenge compared to animals that received BSA alone. There was no significant alteration in airway responsiveness 1 h, 4 h or 72 h after PAF challenge. Exposure of actively sensitised guinea pigs to an aerosol of ovalbumin induced airway hyperresponsiveness to i.v. histamine, 24 h post challenge. PAF induced a selective increase in the percentage of eosinophils in bronchoalveolar lavage fluid 24 h after challenge, that persisted for at least 72 h post challenge. No significant increase in eosinophils was noted 1-4 h after PAF exposure. Antigen challenge of actively sensitised guinea pigs induced a significant increase in the percentage of eosinophils recovered in BAL fluid 24 h post challenge. Pretreatment of both normal and sensitised guinea pigs with the selective PAF antagonist WEB 2170 significantly inhibited both airway hyperresponsiveness and airway eosinophilia 24 h post challenge with aerosol PAF or allergen. These results further support the suggestion that PAF may play a central role in allergen induced eosinophil infiltration and airway hyperresponsiveness in the guinea pig.
authors.affiliation: Department of Pharmacology, King's College, University of London, U.K.
authors.forename: E A
authors.initials: EA
authors.lastname: Seeds
authors.forename: A J
authors.initials: AJ
authors.lastname: Coyle
authors.forename: C P
authors.initials: CP
authors.lastname: Page
mesh_terms: D000336:Aerosols; D000818:Animals; D000941:Antigens / Q000008:administration & dosage*; D001381:Azepines / Q000494:pharmacology*; D016084:Bronchoconstriction / Q000187:drug effects*; D002465:Cell Movement / Q000187:drug effects; D004334:Drug Administration Schedule; D004804:Eosinophils / Q000187:drug effects / Q000276:immunology*; D006168:Guinea Pigs; D006632:Histamine / Q000008:administration & dosage; D008297:Male; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors*; D013997:Time Factors; D014230:Triazoles / Q000494:pharmacology*
chemical_list: D000336:Aerosols; D000941:Antigens; D001381:Azepines; D010972:Platelet Activating Factor; D014230:Triazoles; D006632:Histamine; C063964:bepafant