Neurotensin-induced mast cell degranulation in human jejunal mucosa. Additive effects of IgE or compound 48/80 and inhibition by sodium cromoglycate.

The effect of sodium cromoglycate (SCG) on neurotensin- and compound 48/80-induced mast cell degranulation and the effect of combining these secretagogues with each other and with an immunological mast cell degranulation system was studied. Neurotensin reduced the number of intact mast cells from 119 (60-190)/mm2 to 50 (20-101)/mm2. This figure was 76 (34-164)/mm2 when SCG was added to neurotensin, a change that was statistically significant. No such inhibitory effect on mast cell degranulation was seen when SCG was added to compound 48/80, which was active only in high doses. When neurotensin or compound 48/80 was followed by antigen in sensitized tissue specimens, mast cell degranulation was enhanced compared with that taking place with only one of the secretagogues. Neurotensin and compound 48/80 did not cause further mast cell degranulation when applied after IgE followed by antigen or when applied after one another. It is concluded that neurotensin may act through a selective release mechanism, whereas compound 48/80 acts by a cytotoxic mechanism, but that they act on the same group of cells.