Ultrastructure of the zymogenic-cell lineage in abomasal mucosa of adult cattle.
The ultrastructural differentiation and maturation of the neck cells and the zymogenic cells during physiological cell renewal were investigated in the abomasal oxyntic-gland region of cattle. Immature neck cells of the distal isthmus and proximal neck exhibit transitional morphology to the predominantly mucous isthmus cells. Neck cells confined to the glandular neck are characterized by bipartite peptic-cored mucous secretory granules. In a proximal-distal gradient along the neck, a progressive increase in the peptic granular component and concomitant reduction in mucous components paralleled by proliferation of the rough endoplasmic reticulum creates pre-zymogenic cells in the proximal glandular base. These, in turn, give rise to mature zymogenic cells with pure peptic secretory granules and typical zymogenic cell morphology. In the depth of the gland, older degenerative zymogenic cells are found. Variations in size and number of the zymogenic granules point to different secretory activities of the mature zymogenic-cell population of the glandular base. These results favour the conception of a zymogenic-cell lineage arising within the isthmus and passing through different developmental stages, including neck cells, during their migration down the gland.
Kressin
M
M
Department of Veterinary Anatomy, Histology and Embryology, University of Giessen, Germany.
D000018:Abomasum / Q000166:cytology / Q000201:enzymology / Q000648:ultrastructure*; D000818:Animals; D002417:Cattle / Q000033:anatomy & histology* / Q000378:metabolism; D019872:Chief Cells, Gastric / Q000201:enzymology / Q000648:ultrastructure*; D004792:Enzyme Precursors / Q000096:biosynthesis*; D005753:Gastric Mucosa / Q000166:cytology / Q000201:enzymology / Q000648:ultrastructure*; D008854:Microscopy, Electron / Q000662:veterinary
D004792:Enzyme Precursors