Arachidonic acid metabolites lipoxygenases

The biological actions of the cysteinyl leukotrienes are mediated via stimulation of CysLTi receptors. Montelukast and zafirlukast are competitive antagonists of these receptors. In contrast, zileuton suppresses synthesis of the leukotrienes by inhibiting 5-lipoxygenase, a key enzyme in the bioconversion of arachidonic acid to the leukotrienes. Zileuton also blocks the production of leukotriene B4, another arachidonic acid metabolite with proinfiammatory activity. The CysLTi-receptor antagonists alter neither the production nor the actions of leukotriene B4. 

Massey KD, Minnich BN, Burt JM Arachidonic acid and lipoxygenase metabolites uncouple neonatal rat cardiac myocyte pairs. Am J Physiol 1992 263 C494—C501. 

GRF-stimulated GH release is also inhibited by lipoxygenase inhibitors, suggesting participation of some lipoxygenase product(s). However, in this area of research more work is also required to attribute a specific messenger role to these arachidonic acid metabolites. 

Powell WS (1985) Reversed-phase high-pressure liquid chromatography of arachidonic acid metabolites formed by cyclo-oxygenase and lipoxygenases. Analyt Biochem 148 59-69... 

The arachidonate cascade includes the COX pathway to form prostanoids and the lipoxygenase (LOX) pathway to generate several oxygenated fatty acids, collectively called eicosanoids. While the exact mechanism remains unknown, it has been shown that eicosanoids play a dual role in regulating both cell survival and apoptosis in various types of cells [81]. One recent study, for example, demonstrated that arachidonic acid metabolites are involved in the regulation of apoptosis in human polymorphonuclear neutrophil granulocytes [82],... 

Any of the collection of oxygenated metabolites of arachidonic acid that are the product of cyclooxygenase, cytochrome P450, or lipoxygenase pathways. 

The title compounds LTB4, 21 (Z) and 22 (Z), have been synthesized23 by stereoselective reduction with deuterium gas of a 1 1 mixture of the suitable diacetylenic precursors 23 and 24 using Lindlar catalyst or palladium on barium sulphate catalyst (equation 10). Leukotriene B4, a 5-lipoxygenase metabolite of arachidonic acid, playing... 

The title compound 160, a biologically potent metabolite of arachidonic acid metabolism, produced in the 5-lipoxygenase pathway in some mammalian cells127 128, has been synthesized129-131 by the reaction of leukotriene E4, 161, with [l-nC[acetyl chloride in 1.3% yield based on [l-nC] acetyl chloride129 (equation 55). 

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