Juxtaposition of somatostatin cell and parietal cell in the dog stomach

Immunohistochemical and silver impregnation techniques were applied to demonstrate the somatostatin producing D cells in the dog gastric body (oxyntic area). It was revealed that the D cells were frequently in direct contact with parietal cells, either by their cell body invaginated into or crescently attached to a parietal cell or by extending a cytoplasmic process ending in a synaptic button-like swelling. Some D cells and their processes appeared to contact chief cells. This morphological finding is correlated to the hypothesis that the D cells might receive an unknown stimulus, possible a mechanical extension of the gastric wall, and by its secretion, somatostatin, inhibit the release of gastric acid and enzymes. The direct juxtaposition and synapse-like connection of D and parietal cells seem to symbolize the continuity of neurons and endocrine cells (paraneurons) as well as neurotransmitters and hormones.