Role of eicosanoids in regulation of macrophage phagocytic functions by platelet-activating factor during endotoxic shock.

We studied the role of eicosanoids in the regulation of macrophage phagocytic functions by products secreted in heterogeneous populations of macrophages and platelet-activating factor during endotoxic shock. Phagocytic activity depended on the metabolism of arachidonic acid in target macrophages and the ratio between its cyclooxygenase and lipoxygenase metabolites produced by heterogeneous populations of macrophages and affecting target cells. The regulatory effect of platelet-activating factor on phagocytosis was related to its interaction with products of the arachidonic acid cascade. Depending on the quantitative ratio of eicosanoids, platelet-activating factor produced various effects on phagocytic functions of heterogeneous macrophage populations.