Indole Nature of Enterochromaffin Substance

Abstract

THERE are several theories about the nature of the argentaffin substance stored in the enterochromaffin cells of the gastrointestinal mucosa^1–3. At present, Erspamer's 5-hydroxytryptamine theory^4,5 appears to be the most popular and best documented. The identification of the enterochromaffin substance as 5-hydroxytryptamine, however, contrasts with the fact that, by using several histochemical methods, no indole reactions have been obtained on formalin-fixed enterochromaffin granules⁶. We have reconsidered the problem by fixing duodenum, stomach and pancreas of various species, including guinea-pig, rat, mouse, rabbit, horse, pig, monkey and man, with 4 per cent formaldehyde or with 6 per cent glutaraldehyde in 0.1 molar phosphate buffer, pH 7.2, for 24 h.