[Immunopharmacological study of buckwheat hypersensitivity (author's transl)]

Effect of dialysate from buckwheat extract on immediate hypersensitivity reactions. To investigate the hypersensitivity reaction of buckwheat, the aqueous extract of buckwheat was separated into dialysate (BWD) and non-dialysate (BWND). BWD neither decreased a release of anaphylactic mediator from the chopped lung tissue nor inhibited Schultz-dale reaction in the ileum of guinea pig sensitized with BWND. Heterologous PCA mediated by rabbit anti-BWND serum in guinea pig and homologous PCA in rats using anti-BWND IgE serum were inhibited by i.d. or i.v. treatment of BWD. Radioallegosorbent test (RAST) and PK reaction were inhibited in a dose dependent fashion by BWD mixed with human serum sensitive to buckwheat, although BWD required approximately 10,000 times more than BWND to produce a RAST inhibition. RAST, however, was not affected when BWD was added to 125I-labelled anti-human IgE. Anti-buckwheat IgE antibody in sensitized animals and atopic patients was specifically absorbed with an insoluble copolymer of BWD-conjugated BSA. BWD did not form a precipitin line against anti-BWND IgG antibody in immunoelectrophoresis. Rat IgE serum-induced degranulation and histamine release from mast cells were inhibited in a dose dependent fashion by BWD and the inhibition was specific to anti-BWND IgE antibody. BWD may be useful as an hyposensitization agent in buckwheat hypersensitivity, since BWD is a haptenic substance capable of neutralizing specific IgE antibody on mast cells.