Synthesis of prostaglandins and leukotrienes. Effects of ethanol

Prostaglandins, thromboxane, and leukotrienes are metabolites of arachidonic acid that have a variety of physiological effects at low concentrations. Effects include smooth muscle contraction, platelet aggregation, platelet disaggregation, bronchoconstriction, increased capillary permeability, cardiac dysfunction, and polymorphonuclear leukocyte accumulation. Although their formation does not appear to be essential for life, these eicosanoid activities are wide ranging and have important roles in normal physiology as well as pathophysiology. At the center of eicosanoid biosynthesis lies the plasma cell membrane which serves as the arachidonic acid reservoir. It has been widely appreciated that ethanol exerts effects on the lipid bilayer, and it is not surprising that a growing body of evidence supports the concept that important interactions between ethanol and eicosanoid biosynthesis can occur. Furthermore, at various steps leading to ultimate prostaglandin, thromboxane and leukotriene production, reactive intermediates such as radicals are involved whose lifetime in the biological milieu can be profoundly modulated by ethanol.