RT Book, Section A1 Smyth, Emer M. A1 Grosser, Tilo A1 FitzGerald, Garret A. A2 Brunton, Laurence L. A2 Hilal-Dandan, Randa A2 Knollmann, Björn C. SR Print(0) ID 1162540122 T1 Lipid-Derived Autacoids: Eicosanoids and Platelet-Activating Factor T2 Goodman & Gilman's: The Pharmacological Basis of Therapeutics, 13e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781259584732 LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1162540122 RD 2024/03/28 AB Membrane lipids supply the substrate for the synthesis of eicosanoids and platelet-activating factor (PAF). Arachidonic acid (AA) metabolites, including PGs, PGI2, TxA2, LTs, and epoxygenase products of CYPs, collectively the eicosanoids, are not stored but are produced by most cells when a variety of physical, chemical, and hormonal stimuli activate acyl hydrolases that make arachidonate available. Membrane glycerophosphocholine derivatives can be modified enzymatically to produce PAF. PAF is formed by a smaller number of cell types, principally leukocytes, platelets, and endothelial cells. Eicosanoids and PAF lipids function as signaling molecules in many biological processes, including the regulation of vascular tone, renal function, hemostasis, parturition, GI mucosal integrity, and stem cell function. They are also important mediators of innate immunity and inflammation. Several classes of drugs, most notably NSAIDs (see Chapter 38), including aspirin, owe their principal therapeutic effects—relief of inflammatory pain and antipyresis—to blockade of PG formation.