Novel insights in the role of peripheral corticotropin-releasing factor and mast cells in stress-induced visceral hypersensitivity.

Visceral hypersensitivity is one of the hallmarks in irritable bowel syndrome (IBS) pathophysiology. Stress is well known to affect visceral sensitivity in humans and rodents, an effect which is associated in part with alterations of intestinal epithelial permeability in rodents. Although the pathophysiology of visceral hypersensitivity is still unclear, two key factors have been identified as playing a major role in its modulation, namely peripheral corticotropin-releasing factor (CRF) and mast cells. In a recent study in Neurogastroenterology and Motility, van den Wijngaard et al. demonstrate that the mast-cell dependent visceral hypersensitivity observed in maternally separated rats after an acute exposure to a psychological stress can be prevented but not reversed by the peripherally restricted CRF receptor antagonist, α-helical CRF(9-41). They further show that the preventive effect of the CRF receptor antagonist is linked to a stabilization of mast cells and maintenance of the epithelial barrier at the colonic level. These data suggest that post stress mast cell activation and subsequent visceral hypersensitivity are not targeted by peripheral CRF receptor antagonists. These novel insights in the role of peripheral CRF in the modulation of stress-induced visceral hypersensitivity add to our growing understanding of the mechanisms that may lie at the origin of visceral pain disturbances following stress and will contribute to enhance the development of drugs that may have potential therapeutic benefits for IBS patients.