Eicosanoids are produced by microglia, not by astrocytes, in rat glial cell cultures

To determine principal sources of eicosanoid production in glial cells, we analyzed the metabolites of arachidonic acid in cultured rat glial cells by use of reversed-phase, high-performance liquid chromatography and an on-line radioisotope detector. Prostaglandin D2, leukotriene B4, leukotriene C4, and 5-hydroxyeicosatetraenoic acid were present in cultures in which microglia appeared on a monolayer astrocytes. None were detected in culture dishes that contained only astrocytes, although astrocytes have been believed to be a main source of eicosanoid production in brain.