Presence of cells and fibers immunoreactive toward antibodies to different peptides or amine in the digestive tract of the snail Helix aspersa

An immunocytological study of four different parts of the gut of Helix aspersa clearly demonstrates the presence of many cells and fibers immunoreactive toward antibodies directed to vertebrate (α, β‐endorphin, α, β‐MSH, ACTH 1–24 and ACTH 17–39, met‐enkephalin, somatostatin, insulin, glucagon, P.P., serotonin) or invertebrate (FMRF‐amide) peptides. These results are evidence of the presence of different substances related to known peptides or amines in the epithelial and connective tissue cells and nerve fibers of the snail gut. Immunocytochemistry may help to elucidate the morpho‐functional characteristics of the enteroendocrine cells of H. aspersa .