Mouse Stomach, Pancreas, Endocrine Cells In The Morphological Study

Objective: To observe the ultrastructure of endocrine cells in the mucosa of the mouse stomach. Meanwhile, to identify the relations between these endocrine cells and other cells, such as the chief cells and parietal cells. Methods: Using the transmission electron microscope to observe the ultrastructure and the anatomical location of endocrine cells, chief cells and parietal cells. Results: Under the electron microscope, the endocrine cells in the mucosa could be divided into three types. Namely type-I, II, III based on their ultrastructure characteristics of the secretory granules. In the endocrine cell type-I there were two kinds of secretory granules. One was vesicle-like, in which were a small, eccentrically located electron-dense core and a thick electron-lucent halo between the encircling membrane and the dense core. The other was membrane-enclosed too with a dense core , homogeneous or not. A thin lucent halo lay between the membrane and the dense core. Besides the granules, there were numerous cytoplasmic vesicles in the cytoplasm. Granules in endocrine cell type-II were membrane-enclosed displaying a homogeneous low electron-density core and a thin lucent halo between the membrane and the core. In endocrine cell type-III there were also two kinds of granules, One had a homogeneous and electron-dense core,with or without a narrow interstice between the core and the encircling memberane. And ,sometimes a much more electron-dense micro-core could be seen in the homogeneous one. While the other kind of granule had a homogeneous or heterogeneous core with the low electron density. Also a comparatively wide interstice could be seen between the core and the encircling membrane. All types of endocrine cells were in contact with the chief cells or parietal cells, the"Ω"-like form could appear on the endocrine cell membrane. Conclusion: In this study endocrine cell type I could be basically confirmed as Enterochromaffin like cell (ECL cells), which mostly adjoined the chief cells and the parietal cells. Therefore, it could be assumed that functionally ECL cells not only could influence the acid secretion by the parietal cells but also have a close relation with the chief cells. Furthermore, the endocrine cells in the mucosa of the body of the stomach also had a paracrine effect on the adjacent cells.