title: Leukotriene B4: an inflammatory mediator with vascular actions in vivo.
abstract: Leukotriene B4 (LTB4) is a 5, 12-dihydroxy derivative of arachidonic acid generated by a variety of inflammatory cells via the lipoxygenase enzyme system. In vitro leukotriene B4 is a potent chemotactic and aggregatory agent; enhances neutrophil complement receptors; stimulates membrane calcium changes and causes contraction of lung parenchyma. In vivo LTB4 is a potent stimulator of vascular permeability in rats, rabbits, guinea-pigs and man particularly in the presence of a vasodilator such as PGE2. LTB4 causes a profound transient neutropenia and massive accumulation of neutrophils when injected into the dermis (rabbit and man), skin chambers (rabbit and man) or body cavities (guinea-pig, rat).
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects; D002199:Capillary Permeability / Q000187:drug effects*; D002633:Chemotaxis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007249:Inflammation / Q000209:etiology*; D007975:Leukotriene B4 / Q000096:biosynthesis / Q000502:physiology*; D009504:Neutrophils / Q000187:drug effects
chemical_list: D001095:Arachidonic Acids; D007975:Leukotriene B4