Eicosanoid signalling

Like nitric oxide, the discovery of the eicosanoid signalling molecules was a significant event in twentieth century physiology, due largely to research led by Sir John Vane (Nobel Prize 1982). The diverse actions of the eicosanoids include roles in muscle contraction, blood coagulation, salt and fluid homeostasis, inflammatory responses and pain sensitivity. 

Marks, F., Muller-Decker, K., and Furstenberger, G., A causal relationship between unscheduled eicosanoid signaling and tumor development cancer chemoprevention by inhibitors of arachidonic acid metabolism, Toxicology, 153, 11, 2000. 

Fimiani C, Liberty T, Aquirre AJ, Amin I, Ali N, Stefano GB (1999a) Opiate, cannabinoid, and eicosanoid signaling converges on common intracellular pathways nitric oxide coupling. Prostaglandins Other Lipid Mediat 57 23-34... 

Soberman RJ, Christmas P. The organization and consequences of eicosanoid signaling. J Clin Invest 2003 111 1107-1113. 

Histidine Essential fatty acids Omega 6 (a)6 or n-6) 28 1-4 % of total calories 8-12 Absolutely required. Enter cell membranes and affect many biochemical processes. The C20 acids are also converted to eicosanoids, signaling molecules that include prostaglandins and leukotrienes. Essential fatty acids protect against cardiovascular disease, disease, inflammation, and autoimmune reactions. 

Howlett, AC, Mukhopadhyay S, Shim J-Y, Welsh WJ. Signal transduction of eicosanoid CB1 receptor ligands. Life Sci 1999 65 617-625. 

Felder CC, Briley EM, Axelrod J, Simpson JT, Mackie K, Devane WA. Anandamide, an endogenous cannabimimetic eicosanoid, binds to the cloned human cannabinoid receptor and stimulates receptor-mediated signal transduction. Proc Natl Acad Sci USA 1993 90 7656-7660. 

Special tasks. Some lipids have adopted special roles in the body. Steroids, eicosanoids, and some metabolites of phospholipids have signaling functions. They serve as hormones, mediators, and second messengers (see p.370). Other lipids form anchors to attach proteins to membranes (see p.214). The lipids also produce cofactors for enzymatic reactions—e.g., vitamin K (see p.52) and ubiquinone (see p.l04). The carotenoid retinal, a light-sensitive lipid, is of central importance in the process of vision (see p.358). 

The eicosanoids are a group of signaling substances that arise from the C-20 fatty acid arachidonic add and therefore usually contain 20 C atoms (Greek eicosa = 20). As mediators, they influence a large number of physiological processes (see below). Eicosanoid metabolism is therefore an important drug target. As short-lived substances, eicosanoids only act in the vicinity of their site of synthesis (paracrine effect see p.372). 

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