Leukotrienes are autocrine and paracrine eicosanoid lipid mediators derived from arachidonic acid by 5-lipoxygenase.

History and name

The name leukotriene comes from the words leukocyte and triene (a compound with three double bonds). What would be later named leukotriene C, "slow reaction smooth muscle-stimulating substance" (SRS) was originally described in 1938 by Feldberg and Kellaway. The researchers isolated SRS from lung tissue after a prolonged period following exposure to snake venom and histamine.

Biochemistry

Synthesis

Leukotrienes are synthesized in the cell from arachidonic acid by 5-lipoxygenase. The lipoxygenase pathway is active in leukocytes and in macrophages and synthesizes leukotrines.

Function

Leukotrienes act principally on a subfamily of G protein coupled receptors. They may also act upon peroxisome proliferator-activated receptors. Leukotrienes are involved in asthmatic and allergic reactions and act to sustain inflammatory reactions; several leukotriene antagonists are used to treat asthma.