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

We examined the effect of sulfapyridine on mast cell-mediated immediate-typ e allergic reactions. Sulfapyridine (1 and 10 mu g/kg) significantly inhibi ted systemic allergic reaction induced by compound 48/80 in rats. Sulfapyri dine (1 and 10 mu g/kg) also inhibited significantly local mast cell-mediat ed immediate-type allergic reactions activated by anti-dinitrophenyl (DNP) IgE. Moreover, sulfapyridine inhibited histamine release dose-dependently i n 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, transient ly and significantly increased about 4-fold compared with that of basal cel ls. These results indicate that sulfapyridine inhibits mast cell-mediated i mmediate-type allergic reactions in vivo and in vitro.