A group of hormones that cause the inflammatory symptoms of hay-fever and asthma.
A group of potent biologic mediators of inflammation consisting of 20 carboxylic acids with at least two oxygen substitutes and three double bonds; derived from arachidonic acid by the lipoxygenase pathway; mediator of inflammatory reactions.
Chemicals released by certain cells (T cells) which “signal” leukocytes (white blood cells). When thus activated, the leukocytes migrate to the site of infection to combat the pathogens.
Eicosanoids synthesized from arachidonic acid.
A group of naturally occurring, slow-reacting substances (SRSS) which have powerful smooth-muscle stimulating properties, particularly on bronchial smooth muscle. Leukotrienes are a metabolic derivative of prostaglandins. Leukotriene receptor antagonists, such as montelukast and zafirlukast, are drugs useful in asthma.
Any of a group of arachidonic acid metabolites that functions as a chemical mediator of allergic reactions and inflammation. Leukotrienes C4, D4, and E4 are derived from the precursor molecule leukotriene A4. The subscripted number specifies the number of double bonds in the molecule. All are synthesized by cells in response to inflammation or tissue injury. Leukotrienes have been implicated in the development of the inflammatory responses in asthma, psoriasis, rheumatoid arthritis, and inflammatory bowel disease. They are powerful bronchoconstrictors and vasodilators and mediate the adverse vascular and bronchial effects of systemic anaphylaxis.
A substance generated by cells of the immune system and lung tissue, playing a role in allergic reactions.