Increased Lactate Dehydrogenase Activity in Buccal Epithelium of Zinc-Deficient Rats

Abstract

Previous studies by us and by others have shown that the body weight of rats fed a zinc-deficient diet is significantly lower than that of pair fed controls, but marked hyperplasia and parakeratosis are seen intra-orally in the buccal epithelium. No histologic changes occur in palatal epithelium. This investigation was undertaken to assay lactate dehydrogenase (LDH) activity in the buccal and palatal epithelium in rats fed a zinc-deficient diet. Weanling male Simonsen rats were fed a diet containing 1.2 ppm zinc for a 30-day period. Pair fed controls were fed the same diet containint 40 ppm zinc. LDH levels were determined by ultramicrochemical assay. In the buccal epithelium, a more than twofold increase over that of controls was observed in zinc-deficient rats, but there was no change in the palatal epithelium. Thse results support the conclusion of others of an organ-specific sensitivity of LDH to zinc deprivation. No increases in LDH activity in zinc-deficient rats, as observed in the hyperplastic buccal epithelium in this study, have previously been reported.

Increased numbers of mast cells in the hyperplastic buccal mucosa of the zinc‐deficient rat

“…The earliest and most consistent response is seen in buccal mucosa (Alvares & Meyer 1968). By 4 weeks on a zinc-deficient diet, the epithelium of the buccal mucosa is markedly hyperplastie; the rate of cell proliferation is accelerated (Alvares & Meyer 1973), the cells of spinous and granular layers are hyper-trophic (Meyer & Alvares 1974), activities of enzymes are increased (Gerson & Meyer 1977), and the keratin layer is parakeratotie and appears disproportionately thickened (Chen et al 1975).…”

Comparison of riboflavin, vitamin A, and zinc status of Chinese populations at high and low risk for esophageal cancer

“…Deficiencies of riboflavin (5), vitamin A (6), and zinc (7) have all been shown to impair the structure of oral or esophageal epithelium. This may increase the degree of contact or susceptibility of the esophageal wall to penetration by environmental carcinogens (8).…”

Zinc and alkaline phosphatase in developing rat oral mucosa

“…Zinc deficiency causes pathological changes in various tissues (2,5,6). Deficient animals develop, among other defects, parakeratotic lesions in the oral mucosa and the skin with thickening of epidermis, intra-and inter-cellular edema, and increased mitotic and metabolic activity (2,(7)(8)(9)(10)(11)(12)(13)(14). This points to a zinc dependence of keratinizing epithelial cells (15), but the function of zinc in epithelium is unknown.…”