Comparison of the anaphylactoid response induced in rats by castanospermine and dextran.

The plant alkaloid castanospermine (10 mg/kg or higher, i.p.; 400 mg/kg, p.o.) induced in some rat strains an anaphylactoid reaction similar to that induced by dextran, i.e. erythema and edema of the snout, ears and paws, for several hours after administration. 86% of the rats from a responsive strain responded to castanospermine while 79% responded to dextran. Rats which responded to castanospermine showed marked, but transient, tachyphylaxis to a second dose of castanospermine or dextran. Rats maintained on a complex-carbohydrate-free diet also responded to castanospermine, excluding the possibility that the effect was due to absorption of dextran-like, dietary, complex carbohydrates. These data raise the possibility that some apparent food allergies in man could be due to the presence in the diet of plant alkaloids with properties similar to those of castanospermine.