Impact of corticotropin-releasing hormone on gastrointestinal motility and adrenocorticotropic hormone in normal controls and patients with irritable bowel syndrome

Background - Corticotropin-releasing hormone (CRH) plays a key role in modulating intestinal motility in stressed animals. Aims - To evaluate the effect of CRH on intestinal motility in humans and to determine whether patients with irritable bowel syndrome (IBS) have an exaggerated response to CRH. Subjects - Ten IBS patients diagnosed by Rome criteria and 10 healthy controls. Methods - CRH (2 χ/kg) was intravenously administered during duodenal and colonic manometry and plasma adrenocorticotropic hormone (ACTH) was measured by radioimmunoassay. Results - CRH induced motility of the descending colon in both groups (p<0.001) and induced greater motility indexes in IBS patients than in controls (p<0.05). CRH produced duodenal phase III motor activity in 80% of the subjects and duodenal dysmotility in 40% of IBS patients. Abdominal symptoms evoked by CRH in IBS patients lasted significantly longer than those in controls (p<0.05). CRH induced significant increases in plasma ACtH levels in both groups (p<0.001) and produced significantly higher plasma ACTH levels in IBS patients than in controls (p<0.001). Conclusion - Human intestinal motility is probably modulated by exogenous CRH. The brain-gut in IBS patients may have an exaggerated response to CRH.