[The role of the beta-adrenoreceptors in the smooth-muscle reactions of the stomach, pyloric sphincter and duodenum to serotonin administration].

Subcutaneous administration of serotonin (10 mg/kg) altered myoelectrical activity of the stomach, pylorus and duodenum in rabbits causing a discoordination of gastroduodenal motor activity. During activation of beta-Adrenoceptors serotonin induced discoordination superimposed on disturbance of normal coordination of the stomach, pylorus and duodenum induced with isopropylnoradrenaline. beta-Adrenoceptor blockade decreased the degree of serotonin-induced discoordination between motility of the stomach and duodenum as concerns the rhythmic component of their activity.