20-trihydroxy-leukotriene-B4 is the metabolite of lipid omega-oxidation of leukotriene B4 (LTB4). LTB4 is the major metabolite in neutrophil polymorphonuclear leukocytes. Omega-oxidation is the major pathway for the catabolism of leukotriene B4 in human polymorphonuclear leukocytes. Leukotrienes are metabolites of arachidonic acid derived from the action of 5-LO (5-lipoxygenase). The immediate product of 5-LO is LTA4 (leukotriene A4), which is enzymatically converted into either LTB4 (leukotriene B4) by LTA4 hydrolase or LTC4 (leukotriene C4) by LTC4 synthase. The regulation of leukotriene production occurs at various levels, including expression of 5-LO, translocation of 5-LO to the perinuclear region, and phosphorylation to either enhance or inhibit the activity of 5-LO. Biologically active LTB4 is metabolized by omega-oxidation carried out by specific cytochrome P450s (CYP4F) followed by beta-oxidation from the omega-carboxy position and after CoA ester formation (PMID: 7649996, 17623009, 2853166, 6088485). Leukotrienes are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways.
belongs to the class of organic compounds known as leukotrienes. These are eicosanoids containing a hydroxyl group attached to the aliphatic chain of an arachidonic acid. Leukotrienes have four double bonds, three (and only three) of which are conjugated.
