[Identification of endocrine cells in the gastrointestinal tract].

The gastric and duodenal endocrine cells (apudocytes) of children and immature rats were studied by electron microscopy. It is shown that every cell type has its own morphological peculiarities of secretory granules formation, maturation and disintegration. This feature together with the size and morphology of mature granules is recommended to be used as a classification criterion for the identification of apudocyte types.