Leukotriene C4

Leukotriene C4

Diagram of eicosanoid synthesis, including leukotriene C4

Leukotriene C4 (LTC4) is a leukotriene, a type of eicosanoid involved in the inflammatory response. It is part of the cysteinyl leukotrienes (CysLTs), which also include leukotriene D4 (LTD4) and leukotriene E4 (LTE4). These molecules are known for their role in asthma and allergic reactions.

Synthesis

Leukotriene C4 is synthesized from arachidonic acid, a polyunsaturated fatty acid, through the lipoxygenase pathway. The enzyme 5-lipoxygenase (5-LO) converts arachidonic acid into leukotriene A4 (LTA4), which is then conjugated with glutathione to form LTC4. This reaction is catalyzed by the enzyme leukotriene C4 synthase.

Function

LTC4 is a potent mediator of inflammation. It acts by binding to cysteinyl leukotriene receptors (CysLT receptors) on target cells, leading to various physiological effects. These include bronchoconstriction, increased vascular permeability, and the recruitment of eosinophils and other inflammatory cells to sites of inflammation.

Role in Disease

Leukotriene C4 plays a significant role in the pathophysiology of asthma and allergic rhinitis. It contributes to the symptoms of these conditions by causing airway constriction and promoting mucus secretion. LTC4 is also involved in other inflammatory diseases, such as atopic dermatitis and anaphylaxis.

Therapeutic Target

Due to its role in inflammatory diseases, leukotriene C4 and its receptors are targets for therapeutic intervention. Leukotriene receptor antagonists, such as montelukast and zafirlukast, are used to treat asthma and allergic rhinitis by blocking the effects of CysLTs, including LTC4.

Related pages

• Leukotriene D4
• Leukotriene E4
• Arachidonic acid
• Lipoxygenase
• Asthma