CENTRAL ACTION OF INTERLEUKIN-1-BETA ON INTESTINAL MOTILITY IN RATS - MEDIATION BY 2 MECHANISMS

Background: Interteukin 1 (IL-1) can influence gut functions by inhibiting gastric acid secretion. This study was performed to investigate the effects of IL-1 on intestinal motility and the mechanisms involved. Methods: The effects of IL- 1β were determined by electromyography in conscious rats with implanted electrodes and a permanent catheter in a lateral brain ventricle. Results: Intracerebroventricular IL-1β (15 ng) administered to fed rats immediately stimulated cecocolonic spike bursts and caused a migrating myoelectric complex pattern after a delay in the small intestine. Tenfold higher doses of peripherally administered IL-1β did not promote similar reactions. The IL-1 antagonist reduced the small intestinal effect of IL-1β and blocked the cecocolonic stimulation. Indomethacin and SC 19220 reduced the small intestinal effects but did not antagonize the increase in cecocolonic contractions. In contrast, α-helical CRF9-41 blocked the increase of cecocolonic contractions but did not antagonize the IL-1β-induced effects on the small intestine. Conclusion: IL-1β's effects on intestinal motility can be mainly ascribed to a central action. The cecocolonic stimulation may be mediated by brain corticotropin-releasing factor, whereas the small intestinal effects involve a prostaglandin mediation. © 1993.