Also found in: Dictionary, Encyclopedia.
Related to leukotrienes: Thromboxanes

leu·ko·tri·enes (LT),

Products of eicosanoid metabolism (usually, arachidonate) with several physiologic roles, such as mediation of inflammation and participation in allergic reactions; leukotrienes differ from the related prostaglandins and thromboxanes in that they do not have a central ring; so named because they were discovered in association with leukocytes and were initially determined to possess three conjugated double bonds; letters A-F identify the first six metabolites isolated, with subscript numbers to indicate the number of double bonds (for example, leukotriene C4).
Farlex Partner Medical Dictionary © Farlex 2012


(LT) (lū'kō-trī'ēnz)
Products of eicosanoid metabolism with physiologic roles in inflammation and allergic reactions.
Synonym(s): leucotriene.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


Powerful chemical agents released by MAST CELLS, basophil cells and MACROPHAGES and involved in many allergic and other immunological reactions. Leukotrienes are derived from ARACHIDONIC ACID and cause CHEMOTAXIS and increase the leakiness of small blood vessels. In asthma they cause the narrowing of the air passages and the secretion of mucus. They can be inhibited by corticosteroid drugs.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


A class of small molecules produced by cells in response to allergen exposure; they contribute to allergy and asthma symptoms.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Effect of montelukast on exhaled leukotrienes and quality of life in asthmatic patients.
When the animals were 12 months old, the equivalent of age 60 in humans, they were treated with zileuton, a drug that inhibits leukotriene formation by blocking the 5-lipoxygenase enzyme.
Prednisolone is an anti-inflammatory drug that reduces prostaglandin and leukotriene synthesis by inhibiting phospholipase-A2, a preoperative, single oral dose of 30mg of prednisolone significantly reduced pain after root canal treatment.9
Cysteinyl leukotrienes are lipid mediators inducing proinflammatory signaling through the activation of specific receptors.
Leukotrienes: mediators of immediate hypersensitivity reactions and inflammation.
Discriminant analysis revealed that these markers included three metabolites (dodecanal, 8-hydroxyguanosine, and leukotriene C4), three proteins (a1-antitrypsin, IgA-uromodulin complex, and galactose-deficient IgA1), and heparan sulfate (Box 2, Figure 1).
Like zafirlukast, montelukast is a competitive antagonist for the cysteinyl leukotrienes. It binds with high affinity and selectivity to the CysLTl receptor subtype.
Previous studies have shown that omega-3 fatty acids are associated with lower risks of cardiovascular disease outcomes, but a recent review (Prostaglandins, Leukotrienes & Essential Fatty Acids, online Sept.
The cyclooxygenase pathway produces the prostaglandins and the lipoxygenase pathway the leukotrienes. The production of these lipid mediators can be affected by inhaled materials; for instance, tobacco smoke has been shown to inhibit the production of leukotriene B4 by human alveolar macrophages [27].
Cysteinyl leukotrienes (cysLTs), specifically LTs [C.sub.4], [D.sub.4], and E4, are generated predominantly by cells of the innate immune system following exposure to allergens, proinflammatory cytokines, and other types of receptor-dependent stimuli.