The effects of indomethacin on the tone and spontaneous activity of the human small intestine in vitro.

The effects of indomethacin on the tone and spontaneous activity of muscle strips from the human terminal ileum were studied. On the longitudinal muscle layer indomethacin caused a loss of tone and a decrease in spontaneous activity. If the drug was added at the beginning of the experiment then the characteristic increase in tone was not observed. On the circular muscle layer indomethacin either initiated or markedly increased spontaneous activity of the muscle strips. Evidence from the in vitro experiments suggests that prostaglandins may be involved in the maintenance of tone of longitudinal muscle and suppression of spontaneous activity in circular muscle from the human terminal ileum.