Role of serotonin in the recovery of electrical activity in the stomach and small intestine of rats during the early postsurgery period.

The effects of serotonin and 5-HT4 receptor agonist cisapride on electrical activity of the stomach and small intestine were studied in rats with postoperative ileus. Postoperative ileus was accompanied by the absence of the migrating myoelectric complex in the stomach and small intestine. All phases of the migrating myoelectric complex were successively recovered in the jejunum, duodenum, and stomach. Administration of serotonin and 5-HT4 receptor agonist cisapride into the jejunum was followed by the appearance of spike activity, which spread from the stomach to the jejunum. Intraintestinal treatment with cisapride and serotonin shortened the period to recovery of the migrating myoelectric complex to 3 and 4 days, respectively. Our results suggest that serotonin plays a role in the regulation of the migrating myoelectric complex at the early postoperation period.