Prostaglandins and Leukotrienes

This chapter is not intended for the prostaglandin (PG) specialist, but rather for those not familiar with the PG field. It will provide a brief overview of the biology of the eicosanoid family and how these local mediators may function in health and in disease. The term “eicosanoids” was coined to describe the broad group of compounds derived from C 20 fatty acids, which, in turn, are derived from the essential dietary fatty acids. The predominant C 20 fatty acid precursor for eicosanoid biosynthesis in most mammals is arachidonic acid (AA). The eicosanoids include the prostaglandins (PGs) and thromboxanes (TXs), the leukotrienes (LTs), the lipoxins (LPXs), and the hydroxyeicosanoic acids (HETEs). Since the biological activity of eicosanoids is rapidly destroyed both in tissues and in the circulation, it is likely that they act locally at the tissue and organ level, where they may regulate regional blood flow and other metabolic Moreover, their formation in various inflammatory sites indicates an important mediating role for these substances in diseased states. Indeed, eicosanoid inhibition by different classes of anti-inflammatory drugs underlines their importance in this regard. The chapter includes a brief historical background, together with a description of nomenclature, biosynthesis, and selected local actions of eicosanoids. For those requiring more detailed information, recent reviews and references on specific topics are included.