Unique functional characteristics of mucosal mast cells.

Mast cells have been isolated from the intestine (IMC) of rats previously infected with the nematode, Nippostrongylus brasiliensis. Functional studies on IMC have shown that they are responsive to antigen and possess surface IgE but, in contrast to peritoneal mast cells (PMC), IMC are unresponsive to the basic secretagogues, 48/80 and bee venom peptide 401, and hyporesponsive to ionophores. Furthermore, sodium cromoglycate, AH9679 and theophylline inhibited secretion by PMC but not IMC, whereas doxantrazole inhibited secretion by both cells. Histochemical investigations established that there is mast cell heterogeneity in the human intestine as well as in the rat. Since GALT and BALT are important in intestinal mastocytosis it is important to determine whether the distinct functional properties of IMC reflect a distinct precursor population, inducer cell, or other factors in GALT or BALT.