Is platelet-activating factor involved in bronchopulmonary hyperresponsiveness?

: Among the various lipid mediators, platelet-activating factor (PAF) is likely to participate in the development of inflammatory and allergic reactions. Indeed, PAF mimics the symptoms of anaphylactic shock and causes bronchial hyperreactivity in various species. The availability of specific PAF antagonists led to determination of the precise role of this mediator in experimental allergic situations. Here we provide evidence that the bronchopulmonary and inflammatory effects of PAF in the guinea-pig are different depending on the immunological status of the animals. Consequently, the search for novel PAF antagonists should take into account the experimental model developed for studying its implication in allergic reactions and in the accompanying airway inflammation.