Role of intestinal mast cells in modulating gastrointestinal pathophysiology

Objective: This article reviews the current understanding of the pathophysiologic role of intestinal mast cells. Data Source: Up to date English language publications on mast cell characteristics, heterogeneity and functions were used. Recent articles were used to develop and extend novel concepts about the role of intestinal mast cells. Study Selection: Reference sources were selected because of their pertinence to the pathophysiological effects of mast cells in intestinal hypersensitivity. Recent publications on the following topics were emphasized: mast cell proteases in intestinal anaphylaxis; effects of nitric oxide in gastrointestinal pathophysiology; involvement of cytokines derived from mast cells in tissue damage and repair. Results: Mast cells are clearly implicated in the pathology of intestinal disease. Growing evidence suggests physiological roles for mast cells in the protection of tissues from inflammatory damage, and in intestinal maturation. Mast cells can release cytokines, such as tumour necrosis factor-ct and interleukin-10, which were originally thought to contribute to inflammatory damage, but which may also have anti-inflammatory properties. Interestingly, mast cell function can be regulated by nitric oxide, and mast cells themselves are sources of this important mediator. Nitric oxide has protective as well as detrimental effects in the intestine. Conclusions: Intestinal mast cells have physiologic regulatory effects in addition to their pathologic effects. However, relatively little is known about the mechanisms of these regulatory effects. Mast cells are likely in an ongoing fluctuating balance between physiological functions and pathological effects in normal individuals. Poorly known factors can create an imbalance and lead to pathologic reactions.