The anaphylactic release of platelet-activating factor from perfused guinea-pig lungs.

The release of platelet-activating factor (Paf-acether) and of its inactive precursor/metabolite lyso-platelet activating factor (lyso-Paf) from control and sensitized guinea-pig isolated lungs challenged with antigen was investigated. Control guinea-pig lungs perfused either through the pulmonary circulation or through the airways and challenged with antigen did not release Paf-acether. Sensitized guinea-pig isolated lungs perfused through the pulmonary circulation and challenged with antigen released lyso-Paf but not Paf-acether. Sensitized guinea-pig isolated lungs perfused through the airways and challenged with antigen released three times more lyso-Paf and also Paf-acether. These results support a possible role for Paf-acether in respiratory anaphylaxis in the guinea-pig