Physiological and pathophysiological roles of eicosanoids in the microcirculation.

Eicosanoids are important mediators of both physiological and pathophysiological responses of the microcirculation. These biologically active lipid mediators can be produced locally by the cellular elements within the microvasculature (endothelium, pericytes, smooth muscle cells) as well as interstitial cells (e.g. fibroblasts, mast cells) and by various cells in the vascular compartment (e.g. leukocytes, platelets). Transcellular metabolism of intermediates produced by one cell type in close contact with another also has the potential to generate potent metabolites. This review integrates some of the older literature with recent developments in eicosanoid synthesis and release, the molecular advances in the enzymology and receptor specificity of the eicosanoids and the regulation by autocoids and inflammatory mediators. The potential roles of eicosanoids in regulation of local blood flow, vascular reactivity, angiogenesis and leukocyte adhesion and transmigration are discussed.