Leukotriene B: a biologically active release product of polymorphonuclear leukocytes
Arachidonic acid (AA) may be metabolized either by cyclo-oxygenase enzyme systems to form prostaglandins and thromboxanes or by lipoxygenase enzymes to produce mono-, di- and trihydroxy fatty acids via either hydroperoxy or epoxide intermediates1. The biological functions of the products of lipoxygenase pathways of AA metabolism are largely unknown. Activities which have been ascribed to these compounds include SRS-A activity2; chemotactic and chemokinetic activities towards polymorphonuclear leukocytes (PMNs) and eosinophils3; a possible involvement in T lymphocyte activation4 and regulation of the biosynthesis5 of PGI2. PMNs have been shown to release a number of products of the lipoxygenase pathways of AA metabolism when exposed to stimuli6,7 such as the calcium ionophore A23187. The present work describes the release of chemokinetic and aggregating activity from rat and human PMNs exposed to calcium ionophore A23187 and demonstrates that these activities are due to leukotriene B, a metabolite of AA produced by lipoxygenase enzymes.
KeywordsArachidonic Acid Trimethylsilyl Ether Calcium Ionophore A23187 Lipoxygenase Pathway Nordihydroguaiaretic Acid
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