Leukotriene

LTA4 Note the four double bonds, three of them conjugated. This is a common property of A4, B4, C4, D4, and E4.
LTB4
LTC4 is a cysteinyl leukotriene, as are D4 and E4.
LTD4
LTE4

Leukotrienes are a family of eicosanoid inflammatory mediators produced in leukocytes by the oxidation of arachidonic acid (AA) and the essential fatty acid eicosapentaenoic acid (EPA) by the enzyme arachidonate 5-lipoxygenase.[1][2][3]

Leukotrienes use lipid signaling to convey information to either the cell producing them (autocrine signaling) or neighboring cells (paracrine signaling) in order to regulate immune responses. The production of leukotrienes is usually accompanied by the production of histamine and prostaglandins, which also act as inflammatory mediators.[4]

One of their roles (specifically, leukotriene D4) is to trigger contractions in the smooth muscles lining the bronchioles; their overproduction is a major cause of inflammation in asthma and allergic rhinitis.[5] Leukotriene antagonists are used to treat these disorders by inhibiting the production or activity of leukotrienes.[6]

  1. ^ Loick, H.; Theissen, J. (1994). "Die Eicosanoide als Mediatoren beim ARDS" [Eicosanoids as mediators in ARDS]. Anästhesiologie, Intensivmedizin, Notfallmedizin, Schmerztherapie (in German). 29 (1): 3–9. doi:10.1055/s-2007-996677. PMID 8142566.
  2. ^ Salmon, John A; Higgs, Gerald A (1987). "Prostaglandins and leukotrienes as inflammatory mediators". British Medical Bulletin. 43 (2): 285–96. doi:10.1093/oxfordjournals.bmb.a072183. PMID 2825898.
  3. ^ O'Byrne, Paul M.; Israel, Elliot; Drazen, Jeffrey M. (1997). "Antileukotrienes in the treatment of asthma". Annals of Internal Medicine. 127 (6): 472–80. doi:10.7326/0003-4819-127-6-199709150-00009. PMID 9313005. S2CID 21480605.
  4. ^ White, Martha (1999). "Mediators of inflammation and the inflammatory process". The Journal of Allergy and Clinical Immunology. 103 (3 Pt 2): S378-81. doi:10.1016/S0091-6749(99)70215-0. PMID 10069896. Retrieved 8 June 2019.
  5. ^ Nelson, David L.; Cox, Michael M. (2008). "Leukotrienes". Lehninger Principles of Biochemistry (5th ed.). Macmillan. p. 359. ISBN 978-0-7167-7108-1.
  6. ^ Scott JP, Peters-Golden M (September 2018). "Antileukotriene agents for the treatment of lung disease". Am. J. Respir. Crit. Care Med. 188 (5): 538–544. doi:10.1164/rccm.201301-0023PP. PMID 23822826.