Abstract
The endocrine cells in the fundic mucosa of the human stomach taken by biopsy using a fiber-gastroscope were examined under the electron microscope.
1. The endocrine cells are concentrated in the deeper portion of the fundic glands. More or less flattened in shape, they lie on the basement membrane towards which the secretory granules of the cell are accumulated.
2. In contrast to the endocrine cells in the pyloric antrum and duodenum which open to the lumen with a cytoplasmic process, the corresponding cells in the human gastric fundus are enclosed in the basal part of the epithelium. The possible functional significance of these open and closed cell types was discussed.
3. Five different cell types were identified in the fundic endocrine elements: (1) EC cells; (2) second type cells with large, round and dense granules; (3) third type cells with small, round granules and ample cytoplasmic filaments; (4) EC-like cells with small, polymorphous granules and numerous small mitochondria; and (5) D-like cells whose granules appeared identical with pancreatic D cell granules.
4. On the basis of the structures of the cell, every one of these cell types is supposed to produce a hormone of proteinic (polypeptide) nature, either known or unknown.
