Prostanoids, including prostaglandins and thromboxanes, are generated by the phospholipase A(2)/cyclooxygenase pathway, and leukotrienes are generated by the 5-lipoxygenase pathway from arachidonic acid. At physiological concentrations, vasodilator prostaglandins enhance the vascular permeability effects of histamine and bradykinin, and leukotrienes are important mediators of leukocyte accumulation during acute inflammation. On the other hand, prostaglandin metabolites such as cyclopentenone prostaglandins contribute to the resolution of acute inflammation through inhibition of nuclear factor-chiB activation. Thus, arachidonic acid oxygenation products mediate diverse effects that induce and resolve acute inflammation caused by bacterial infection. Curr Opin Infect Dis 14:257-263. (C) 2001 Lippincott Williams & Wilkins.