Prostaglandin E(2) augments bradykinin-induced discharges of polymodal receptors as studied in vitro preparations. The antagonist and agonists for three subtypes of EP receptors were used to determine which subtype is involved in this phenomenon. The agonist for EP(3) (M&B28767) simulated the PGE(2)-induced effect but not for EP(2) (butaprost). The antagonist for EP(1) (AH6809) did not suppress the effect. These findings indicate the involvement of the EP(3) receptor subtype in the effect.