The role of mast cells in common gastrointestinal diseases.

The gastrointestinal tract is a rich source of mast cells with an enormous surface area that permits a high degree of interaction between the mast cell and the intestinal contents. The active metabolic products of the mast cell influence gastrointestinal secretion, absorption, and motility through paracrine effects of local mast cell activation and also cause systemic effects through the release of cellular products into the bloodstream. Recent advances in our knowledge of the immune system and the recognition that the gastrointestinal immune function might be partially mediated through gastrointestinal mucosal mast cells has opened mast cell research to the field of gastroenterology. Local gastrointestinal proliferation of mast cells in response to recognized or obscure stimuli can alter gastrointestinal function and induce systemic symptoms. Symptoms can arise from the increased number of mast cells, overproduction of specific mast cell mediators, and hyperactivity of the enteric nervous system that induces mast cell activation. The diseases mentioned in this review represent a small proportion of areas where mast cell function might play an important role in the response to disease and generation of symptoms.