ULTRASTRUCTURE OF THE CARDIAC AND PYLORIC GLANDS OF THE GASTRIC-MUCOSA OF THE SOUTH-AFRICAN HEDGEHOG, ATELERIX-FRONTALIS

The cardiac and pyloric glands in the gastric mucosa of the South Afri can hedgehog, Atelerix frontalis, are described. The cardiac area of t he stomach contains proper cardiac glands and lacks undifferentiated f undic glands. The cardiac glands are simple tubular, coiled, and lined with columnar cells ultrastructurally similar to those of the gastric surface epithelium. Secretory granules with varying electron densitie s fill the apical cytoplasm of these cells. In contrast to other mamma ls, these glands lack mucous neck cells. The neck of the pyloric gland s contains only a single cell type, whereas the basal regions of these glands contain ''light'' and ''dark'' cells. The secretory granules i n the ''dark'' cells and the pyloric neck cells have a moderate electr on density and often contain an electron dense core. An electron-lucen t cytoplasm with numerous polysomes is characteristic of the ''light'' cells. Some ''light'' cells contain electron-dense granules in the ap ical cytoplasm. The presence of only neutral mucins in the cardiac gla nd cells denotes the absence of mucous neck cells. The acidic mucins w ithin the pyloric neck cells seem to indicate that these cells are muc ous neck cells, whereas the neutral mucins within the basally located pyloric gland cells show at least a partial functional difference from the pyloric neck cells.