Gut mucosal mast cells in Nippostrongylus-primed rats are the major source of secreted rat mast cell protease II following systemic anaphylaxis.

The distribution of the predominant chymotrypsin-like enzyme of mucosal mast cells (rat mast cell protease II: RMCP II) was examined in naive and Nippostrongylus-primed rats both before and after the induction of systemic anaphylaxis. Anaphylactic secretion of RMCP II following i.v. challenge of primed rats with worm antigen was accompanied by significant depletion of this enzyme from the jejunal and gastric mucosae; the concentrations were not altered in the ileum and colon. Despite significant increases in the levels of RMCP II in lung and mesenteric lymph node following infection with N. brasiliensis there was no anaphylactic depletion of this enzyme from these sites. No RMCP II was detected in liver, spleen, kidney or bone marrow either before or after systemic anaphylaxis. Mucosal mast cells were depleted from the jejunal, gastric and colonic mucosae following antigen challenge of primed rats. These data provide further evidence that gastrointestinal mucosal mast cells are the major source of secreted RMCP II following systemic anaphylaxis in the rat.