Inhibitory effect of mast cell-mediated immediate-type allergic reactions by sulfapyridine.

We examined the effect of sulfapyridine on mast cell-mediated immediate-type allergic reactions. Sulfapyridine (1 and 10 microg/kg) significantly inhibited systemic allergic reaction induced by compound 48/80 in rats. Sulfapyridine (1 and 10 microg/kg) also inhibited significantly local mast cell-mediated immediate-type allergic reactions activated by anti-dinitrophenyl (DNP) IgE. Moreover, sulfapyridine inhibited histamine release dose-dependently in the rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. When sulfapyridine was added, the level of cAMP in RPMC, transiently and significantly increased about 4-fold compared with that of basal cells. These results indicate that sulfapyridine inhibits mast cell-mediated immediate-type allergic reactions in vivo and in vitro.