Leukotrienes

Leukotrienes are products of the enzyme arachidonate 5-lipoxygenase (5-LO). They are fatty molecules that contribute to inflammation in asthma and allergic rhinitis. Leukotrienes are typically biosynthesized in concert with histamine. ^[1] As the name suggests, arachidonic acid (AA) is a substrate of arachidonate 5-lipoxygenase. ^[2] AA is an omega-6 fatty acid. ^[3] Eicosapentaenoic acid (EPA) is also a 5-LO substrate. ^[2] EPA is an omega-3 fatty acid. ^[4] The 4-series leukotrienes (LTB4, LTC4, LTD4, LTE4) are synthesized from AA. They are generally proinflammatory. The 5-series leukotrienes (LTB5, LTC5, LTD5, LTE5) are synthesized from EPA. They are anti-inflammatory. ^[2] Leukotrienes are released from mast cells as part of the inflammation response. They attract white blood cells to sites of tissue damage and cause smooth muscles to contract. ^[5]

References

1. ↑ http://en.wikipedia.org/wiki/Leukotrienes
2. 1 2 3 http://en.wikipedia.org/wiki/Arachidonate_5-lipoxygenase
3. ↑ http://en.wikipedia.org/wiki/Arachidonic_acid
4. ↑ http://en.wikipedia.org/wiki/Eicosapentaenoic_acid
5. ↑ http://www.answers.com/topic/leukotrienes

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