Immunocytochemical localization of substance P in mammalian intestine

In mammalian intestine immunoreactive Substance P is localized not only in the plexuses of Auerbach and Meissner, as could be anticipated, but also in a number of basally situated, often basigranular, endocrine cells which have been identified tentatively as enterochromaffin. The presence of a neurohormone in cells of this type confirms their close association with the nervous system, noted by Masson (1924), and suggests that their postulated origin from the nervous system (Danisch, 1924) may well be correct.