A cDNA clone for rat thromboxane (TX) A2 receptor was obtained from cultured astrocytes. The cDNA encodes a protein of 341 amino acids with seven putative transmembrane domains. The receptor is homologous with mouse and human TXA2 receptors at 92.7% and 71.8%, respectively. Expression of messenger RNA for the receptor was examined by reverse transcriptase-polymerase chain reaction, showing ubiquitous expression in brain glial cells such as astrocytes, oligodendrocytes and microglia.