Leukotrienes are very important agents in the inflammatory response. Some such as LTB4 have a chemotactic effect on migrating neutrophils, and as such help to bring the necessary cells to the tissue. Leukotrienes also have a powerful effect in bronchoconstriction and increase vascular permeability. Leukotrienes in asthma Leukotrienes contribute to the pathophysiology of asthma, especially in patients with aspirin-exacerbated respiratory disease (AERD), and cause or potentiate the following symptoms: airflow obstruction increased secretion of mucus mucosal accumulation bronchoconstriction infiltration of inflammatory cells in the airway wall Role of cysteinyl leukotrienes Cysteinyl leukotriene receptors CYSLTR1 and CYSLTR2 are present on mast cells, eosinophil, and endothelial cells. During cysteinyl leukotriene interaction, they can stimulate proinflammatory activities such as endothelial cell adherence and chemokine production by mast cells. As well as mediating inflammation, they induce asthma and other inflammatory disorders, thereby reducing the airflow to the alveoli. The levels of cysteinyl leukotrienes, along with 8-isoprostane, have been reported to be increased in the EBC of patients with asthma, correlating with disease severity. Cysteinyl leukotrienes may also play a role in adverse drug reactions in general and in contrast medium induced adverse reactions in particular. In excess, the cysteinyl leukotrienes can induce anaphylactic shock. Leukotrienes in dementia Leukotrienes are found to play an important role in the later stages of Alzheimer's disease and related dementias in studies with animals. In tau transgenic mice, which develop tau pathology, "zileuton, a drug that inhibits leukotriene formation by blocking the 5-lipoxygenase enzyme" was found to reverse memory loss. See also A chemical synthesis of Leukotriene A methyl ester Eoxins (14,15-leukotrienes) References Further reading Bailey, J. Martyn (1985) Prostaglandins, leukotrienes, and lipoxins: biochemistry, mechanism of action, and clinical applications Plenum Press, New York, Lipkowitz, Myron A. and Navarra, Tova (2001) The Encyclopedia of Allergies (2nd ed.) Facts on File, New York, p. 167, Samuelsson, Bengt (ed.) (2001) Advances in prostaglandin and leukotriene research: basic science and new clinical applications: 11th International Conference on Advances in Prostaglandin and Leukotriene Research: Basic Science and New Clinical Applications, Florence, Italy, June 4–8, 2000 Kluwer Academic Publishers, Dordrecht, External links Eicosanoids Immunology Polyenes