title: Effects of zinc deficiency on the distribution of membrane-coating granules in rat buccal epithelium.
abstract: Nutritional zinc deficiency causes consistent excessive cell proliferation in the epithelium of the buccal mucosa. The number per cell and the intracellular location of membrane-coating granules in this epithelium were investigated in male rats placed at weanling age for a 4-week period on a diet containing 1.2 ppm of Zn and in their pair fed controls. Membrane-coating granules were identified on electron micrographs following their demonstration in thin sections by the use of an alkaline bismuth technique. Counts of membrane-coating granules in the first 4 rows of spinous cells and the last 4 rows of granular cells showed that in the zinc-deficient group (1) the total number of granules per cell was increased; (2) the proportion of granules displaced to the cell periphery was decreased in favor of a higher proportion persisting in the center and (3) there was a marked reduction in number and proportion of granules positioned near the superficial cell membrane. The greater uniformity in the distribution of the granules in the hyperplastic-hypertrophic epithelium of the zinc deficient group suggests weakening of the surface-oriented polarity characteristic of the control tissue.
mesh_terms: D000818:Animals; D002610:Cheek / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003594:Cytoplasmic Granules; D004848:Epithelium / Q000648:ultrastructure*; D008297:Male; D009061:Mouth Mucosa / Q000648:ultrastructure*; D051381:Rats; D015032:Zinc / Q000172:deficiency*
chemical_list: D015032:Zinc