Figure 2 .

Effect of atropine and sumatriptan on antral contractile activity induced by erythromycin 200 mg intravenously in a healthy volunteer. All traces begin at the start of the infusion of erythromycin, which lasted 10 minutes. (A) Erythromycin caused a burst of prolonged contractile activity at the antral level that did not migrate to the small intestine and was not followed by a phase 1. (B) Prior administration of atropine did not influence the occurrence of this prolonged antral contractile activity. (C) Prior administration of sumatriptan also did not block the erythromycin induced prolonged antral contractile activity.