Chronic fluoride toxicity: a scanning electron microscopic study of duodenal mucosa.

The effects of chronic fluoride toxicity on duodenal mucosa of rabbits were investigated using scanning electronmicroscope on materials obtained from rabbits subjected to oral administration of sodium fluoride at the dose of 10 mg/kg body weight per day for a period of 24 months. Significant morphological abnormalities were observed in the mucosa of all the fluoride treated animals [n = 9] when compared to that of control rabbits. The surface of the microvilli of duodenal epithelium revealed a "cracked-clay" appearance in fluoride treated rabbits. Besides, abrasion on the villus surface due to epithelial cell degeneration was also noticed. Mucus probably coating the degenerated cells formed strands over the villi in fluoride treated animals.