Leukotrienes and lipoxygenase factors: mediators and modulators of the allergic reaction

Lipoxygenase factors of arachidonic acid (mono- and di-Hetes) are not only mediators but also modulators of inflammatory reactions. They have chemotactic and spasmogenic properties; the latter are similar to those induced by the slow reacting-substance of anaphylaxis (SRS-A). The eosinophil chemotactic factor has been identified as a lipoxygenase product. Among the chemically mono- and di-Hetes the 5-S-12-R di-Hete (LTB4) and the 5-S 12S di-Hete demonstrated the most pronounced eosinophil chemotactic activity. The phospholipase-arachidonic acid sequence is involved in the IgE induced activation and secretion of human basophils. With arachidonic acid analogs the lipoxygenase transformation pathway is inhibited.