Expression level of messenger RNAs (mRNAs) for prostanoid EP3, FP, and TP receptors was investigated in cultured rat astrocytes, oligodendrocytes, and microglia, as well as in meningeal fibroblasts, rat glioma C6 cells, rat pheochromocytoma PC12 cells, whole brain, and several peripheral tissues by reverse transcriptase-polymerase chain reaction. Cultured astrocytes and oligodendrocytes expressed mRNAs for 3 prostanoid receptors examined. In contrast, cultured microglia and pheochromocytoma PC12 cells expressed EP3 and TP receptor mRNAs, but not FP receptor mRNA. Glioma C6 cells expressed only TP receptor mRNA among 3 prostanoid receptors with the same expression level as that in astrocytes. Cultured meningeal fibroblasts expressed 3 receptor transcripts, and their expression levels were lower than those in astrocytes. Expression level of mRNA for each prostanoid receptor in cultured glial cells was higher than that in whole brain. These observations suggest that each prostanoid has its specific roles in each glial cell type of the brain.