Mast cell granules within endothelial cells: a possible signal in the inflammatory process?

Mast cell-endothelial cell interactions have long been suspected to be important in inflammation. The detail of the pathways of communication have yet to be elucidated. In this report we describe, for the first time, mast cell granules within endothelial cells of colonic capillaries in a patient with florid colitis, as well as rats with experimentally induced mast cell degranulation. We postulate that this phenomenon may occur more generally during immunologically mediated inflammatory cell degranulation, and may be one mechanism of communication to endothelium.