Cytochemical and Autoradiographic Study of Nuclei in Zinc-Deficient Rat Buccal Epithelium

Ammoniacal silver stain showed that there was a decrease in nucleohistones in zinc-deficient rat buccal hyperplastic epithelium as compared to control. Autoradiographic study showed that there was decreased incorporation of 3H-argi-nine and 3H-lysine in the hyperplastic epithe-lium. J Dent Res 56(12): 1546-1551, December 1977. Rat buccal epithelium reveals hyperplasia and hyperparakeratosis when rats are fed a zinc-de-ficient diet. 1.2 It has been shown that in this hy-perplastic epithelium, the mitotic rate is higher than that in normal epithelium, the migration rate of cells from the basal layer toward the sur-face is faster, and the cell dry weight is great-er.3 4 Since it has been suggested that nuclear basic proteins (nucleohistones) control the ex-pression of genome activity,5 6 the present study of the nuclear basic proteins in zinc-deficient hyperplastic epithelium was undertaken using cytochemical and autoradiographic techni-ques. Materials and Methods Twenty-eight Simonsen white weanling male rats were used. The rats were randomly sepa-rated into control and experimental groups of equal numbers. Control rats were fed ad libi-tum with a pelleted diet supplemented with 36 mg/kg of zinc. * They were given tap water. Ex-perimental rats were also fed ad libitum with the same diet. No zinc supplement was added to their diet, and its zinc content was assayed at 1.3 mg/kg.t They were given distilled water. The experimental period was 28 days. At the Received for publication January 10, 1977. Accepted for publication February 15, 1977