Figure 1 .

Effect of atropine and sumatriptan on the initiation of an antral activity front by erythromycin 40 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 premature activity front at the antral level that migrated caudally to the small intestine. (B) Prior administration of atropine blocked the generation of a premature activity front by erythromycin during a 60 minute period. (C) Prior administration of sumatriptan also blocked the generation of a premature activity front by erythromycin during a 60 minute period.