ABSTRACT
This chapter reviews studies related to both aspects of eosinophil functioning. It considers some of the aspects pertinent to the intracellular sites and regulation of eosinophil eicosanoid formation. Specific enzymes can be associated with lipid bodies, as indicated by histochemical studies localizing enzymes with nonspecific esterase and peroxidase activities to lipid bodies within eosinophils. Lipid bodies are prevalent in vivo in cells associated with various immune and inflammatory responses and are prominent in eosinophils from patients with eosinophilia, including blood and tissue eosinophils in those with the idiopathic hypereosinophilic syndrome and lesional or tissue eosinophils in varied conditions and responses. The functions of eosinophils in immunological reactions may be multiple, reflecting not only the diverse capabilities of eosinophils but also the heterogeneity of immunopathological alterations encountered in various eosinophil-related diseases. The effector functions of eosinophils utilize acute, potentially agonal, cellular responses, such as degranulation, oxidative burst activity, and eicosanoid release.
