Pharmacology of allergen-induced early and late airway responses and antigen-induced airway hyperresponsiveness in allergic sheep

Abstract

The pharmacology of antigen-induced early and late phase airway responses and the associated antigen-induced airway hyperresponsiveness was studied in allergic sheep. Data from studies with anti-allergic agents and specific receptor antagonists, especially leukotriene antagonists and antagonists of platelet activating factor (PAF), have led to the hypothesis that allergen-induced late responses in allergic sheep are linked to a heightened metabolism of arachidonic acid via the 5-lipoxygenase pathway. This increases leukotriene production during the acute allergic reaction, which results in a more prolonged acute bronchoconstriction and subsequently a more severe airway inflammation. These recruited inflammatory cells can then release mediators and other cell products which contribute to the late response and airway hyperresponsiveness.