Abstract
Endocrine cells in biopsy tissues of human jejunum and ileum were observed under the electron microscope.
1. The endocrine cells were found much less frequently in the jejunum than in the duodenum previously examined. They were still fewer in the ileum.
2. The EC cell was the predominant type. Some variant cells of this type such as those with small-sized granules and with vacuolated granules were noticed.
3. The L or large-granule cell (Type 2 cell in our previous papers) was the second most frequent endocrine element.
4. The S or small-granule cell was found occasionally. This cell, as in the duodenum, is characterized by abundant cytoplasmic filaments. Possible M or medium-granule cell was occasionally seen but the identification was equivocal.
5. A-like cells with granules of double structure resembling the pancreatic A cell granules was found in the jejunum, and its possible relation to enteroglucagon and glucagonlike immunoreactivity (GLI) was discussed.
6. It was remarked that the “Type 3” cells in our previous paper on the duodenum (KOBAYASHI, FUJITA and SASAGAWA, 1970) included S, M and A-like cells.
