Leukotriene E4

Leukotriene E4

0Leukotriene E4 (LTE4) is a bioactive lipid and a member of the leukotriene family. It is produced in the body from leukotriene C4 (LTC4) through the action of the enzyme gamma-glutamyl transpeptidase (GGT). LTE4 is known to play a significant role in the pathophysiology of asthma and allergic rhinitis.

Biosynthesis

The biosynthesis of LTE4 begins with the conversion of arachidonic acid to leukotriene A4 (LTA4) by the enzyme 5-lipoxygenase (5-LO). LTA4 is then converted to leukotriene C4 (LTC4) by the enzyme LTC4 synthase. Finally, LTC4 is converted to LTE4 by the enzyme gamma-glutamyl transpeptidase (GGT).

Function

LTE4 is a potent bronchoconstrictor and vasodilator, and it also increases vascular permeability. It is involved in the pathophysiology of asthma and allergic rhinitis, and it is also implicated in other inflammatory conditions such as chronic obstructive pulmonary disease (COPD) and rheumatoid arthritis.

Clinical significance

Increased levels of LTE4 have been found in the urine of patients with asthma, allergic rhinitis, and atopic dermatitis, suggesting that it may be a useful biomarker for these conditions. In addition, drugs that block the synthesis or action of LTE4, such as montelukast and zafirlukast, are used in the treatment of asthma and allergic rhinitis.

See also

• Leukotriene
• Leukotriene receptor antagonist
• 5-lipoxygenase
• Arachidonic acid