MECHANISM OF INHIBITORY AND STIMULATORY EFFECTS OF SEROTONIN ON DUODENAL CONTRACTIONS

Abstract

Aim. To investigate the effects of serotonin on duodenal motor activity. Materials and Methods. Experiments were performed on Wistar rats (n=83) which received nembutal anesthesia. We further conducted electromyography and measured hydrostatic pressure in the duodenum. Results. Intraarterial administration of 0.05 mg/kg, 0.1 mg/kg, and 0.15 mg/kg serotonin induced inhibitory responses in 29%, 8.3%, and 6.3% of rats, respectively. Other rats, however, showed stimulatory responses or no specific response. Intravenous administration of serotonin did not enhance bowel contractions. Conclusion. Inhibitory responses occurred at low doses of serotonin due to the activation of presynaptic5-hydroxytryptamine (5-HT, serotonin) receptors while stimulatory responses were induced by high doses of serotonin through muscular 5-HT receptors.

Keywords

• двенадцатиперстная кишка
• моторика
• регуляция
• серотонин
• duodenum
• motor activity
• regulation
• serotonin