“…At this time, functional events were paralleled by morphological and biochemical abnormalities, including extensive epithelial damage at the villus tips [7], decreased numbers of stained mast cells in the mucosa [3,4] and high serum levels of the specific protease, RMCP II, supporting ongoing mucosal mast cell activation. Similar increases in Isc [6] and RMCP II [8] as well as histological abnormalities [9] were demonstrated when intestinal tissue was challenged with worm antigen on day 35 after infection, when mast cell hyperplasia had developed, further supporting the view that mast cells are critical in ion transport changes in the inflamed intestine. Investigations in the T. spiralis model led to similar findings and also implicated histamine, serotonin and prostaglandins in the antigen-induced chloride secretion [10,11].…”