Cytology and arrangement of enterochromaffin (EC) cells in the human stomach.

Serotonin containing enterochromaffin (EC) cells in the human gastric mucosa were observed using serial semithin sections immunostained by Sternberger's PAP method and reconstructed by computer-assisted methods. In oxyntic glands, EC cells displayed a marked pleomorphism which suggests their plasticity or active movement. They sometimes possessed multipolar cytoplasmic processes directly contacting the neighboring epithelial cells and/or gastric lumen. In the antropyloric glands, they are exclusively the "closed-type," which fails to contact the lumen, and are often arranged touching other EC cells (cluster formation), apparently exhibiting polynuclear enterochromaffin syncytia. This syncitium-like arrangement is interpreted as the morphological counterpart of a possibly synchronized function of these cells. The morphological differences of EC cells in their shape, luminal endings and arrangement between both regions may be indicative of regional differences in their functions. Furthermore, the present study provides the first three-dimensional visualization of EC cells in the human stomach.