Description_x000D_ Packaging_x000D_ 5, 25 mg in glass bottle_x000D_ Biochem/physiol Actions_x000D_ GR203040 is a high affinity, non-peptide tachykinin NK1 receptor antagonist. GR203040 inhibits substance P binding to human NK1 receptors in CHO cells with a pKi or 10.3. The compound prevents emisis, and reduces bladder damage induced by radiation, cisplatin and cyclophosphamide. 11C-labeled GR203040 is used as a radioligand to image NK1 receptors in the CNS by PET scanning.