description
Eicosanoids, oxygenated, 20-carbon fatty acids, are autocrine and paracrine signaling molecules that modulate physiological processes including pain, fever, inflammation, blood clot formation, smooth muscle contraction and relaxation, and the release of gastric acid. Eicosanoids are synthesized in humans primarily from arachidonic acid (all-cis 5,8,11,14-eicosatetraenoic acid) that is released from membrane phospholipids. Once released, arachidonic acid is acted on by prostaglandin G/H synthases (PTGS, also known as cyclooxygenases (COX)) to form prostaglandins and thromboxanes, by arachidonate lipoxygenases (ALOX) to form leukotrienes, epoxygenases (cytochrome P450s and epoxide hydrolase) to form epoxides such as 15-eicosatetraenoic acids, and omega-hydrolases (cytochrome P450s) to form hydroxyeicosatetraenoic acids (Buczynski et al. 2009, Vance & Vance 2008).Levels of free arachidonic acid in the cell are normally very low so the rate of synthesis of eicosanoids is determined primarily by the activity of phospholipase A2, which mediates phospholipid cleavage to generate free arachidonic acid. The enzymes involved in arachidonic acid metabolism are typically constitutively expressed so the subset of these enzymes expressed by a cell determines the range of eicosanoids it can synthesize.Eicosanoids are unstable, undergoing conversion to inactive forms with half-times under physiological conditions of seconds or minutes. Many of these reactions appear to be spontaneous

external resources
NCBI:82991
KEGG:hsa00590
NCBI:1270087
REACTOME:R-HSA-2142753
PUBMED:14622984
PUBMED:15292194
PUBMED:10908295
PUBMED:15205388
PUBMED:9812980
PUBMED:14660610
PUBMED:11328810
PUBMED:14636671
PUBMED:14626496
PUBMED:11679404
PUBMED:19244215

genes
ALOX12 , ALOX5 , ALOX12B , ALOX15 , ALOX15B , CBR1 , CBR3 , CYP2B6 , CYP2C19 , CYP2C8 , CYP2C9 , CYP2E1 , CYP2J2 , CYP4A11 , EPHX2 , GGT1 , GGT5 , GPX1 , GPX2 , GPX3 , GPX5 , GPX7 , LTA4H , CYP4F3 , LTC4S , PLA2G1B , PLA2G2A , PLA2G4A , PLA2G5 , PTGDS , PTGIS , PTGS1 , PTGS2 , TBXAS1 , PLA2G6 , PLA2G10 , CYP4F2 , PLA2G4C , AKR1C3 , JMJD7-PLA2G4B , PTGES , PTGES3 , PLA2G16 , CYP4F8 , PLA2G2D , HPGDS , PLA2G2E , PLA2G3 , PLA2G2F , PTGES2 , PLA2G12A , PLA2G12B , CYP2U1 , PLA2G4E , FAM213B , PLB1 , PLA2G4F , GPX6 , PLA2G4D , PLA2G2C , GPX8 , PLA2G4B , ALOX5AP , CYP1A1 , CYP1A2 , CYP1B1 , CYP4B1 , CYP8B1 , DPEP1 , FAAH , GPX4 , HPGD , ABCC1 , PON1 , PON2 , PON3 , MAPKAPK2 , PTGR1 , CYP4F11 , DPEP2 , DPEP3 , GGTLC2 , CYP4F22 , PTGR2 , FAAH2 , AWAT1 , CYP4A22 ,