Prostaglandin PGE2 is an important mediators of central sensitization in the human viscera: The EP-1prostinoid receptor antagonist ZD 6416 is a novel therapy in visceral hypersensitivity

acid clearance was evaluated by measuring the duration of time for pH to return to 4.0 after infusion of 15 ml 0.1 N HCI. GER was recorded by pH probe placed 5 cm above the LES. Heartburn symptoms were evaluated by a 0-10 cm visual analogue scale. RESULTS: Chocolate significantly increased reflux events and acid exposure time when compared to 3% NaCl. Granisetron significantly reduced reflux events and tended to reduce acid exposure time. Furthermore, chocolate reduced LES pressure, which was reversed by granisetron. In addition, after chocolate the heartburn symptoms were increased compared to 3% NaCI, which was reduced by granisetron. CONCLUSIONS: We demonstrated that chocolate induces GER symptoms by reducing LES pressure and increasing reflux events and acid exposure duration in GERD patients. These events could be antagonized by granisetron. These results suggest that 5HT3 antagonist may be a novel treatment of GERD.