LEUKOTRIENE B4

Leukotriene B4 is a pro-inflammatory mediator synthesised in myeloid c ells from arachidonic acid. Synthesis is catalysed by 5-lipoxygenase a nd leukotriene A4 hydrolase and is increased by inflammatory mediators including endotoxin, complement fragments, tumor necrosis factor and interleukins. A nuclear membrane protein, 5-lipoxygenase activating pr otein, is an essential co-factor for 5-lipoxygenase. Leukotriene B4 in duces recruitment and activation of neutrophils, monocytes and eosinop hils. It also stimulates the production of a number of proinflammatory cytokines and mediators indicating an ability to augment and prolong tissue inflammation. Elevated levels of leukotriene B4 have been found in a number of inflammatory diseases and levels are related to diseas e activity in some of these. Initial data from pharmacological inhibit ion studies support a role for leukotriene B4 in the pathogenesis of n eutrophil mediated tissue damage, and treatments which reduce its prod uction or block its effects may prove beneficial in neutrophil mediate d inflammatory diseases. (C) 1998 Elsevier Science Ltd. All rights res erved.