Effects of Fluoride on Structure and Function of Canine Gastric Mucosa

Abstract

These studies were done to determine the effectsof fluoride (F) on the structure and function of thecanine gastric mucosa and the possible protectiveeffects of 16,16-dimethylprostaglandin E₂(dmPGE₂). A portion of the stomach with its vascularsupply intact was mounted in a two-compartment chamber,one side of which contained a control solution. Minoreffects were caused by exposure to 1 mmol/liter F. Both 5 and 10 mmol/liter F caused markedincreases in the fluxes of water and Na, K, and H ions;mucus secretion; and tissue swelling and redness. Theextent of these changes did not increase appreciably upon exposure to 50 or 100 mmol/liter F.Histological findings included marked thinning of thesurface cell layer, reduced uptake of PAS stain,localized exfoliation and necrosis of surface cells,acute gastritis, and edema. It was concluded that:(1) the threshold F concentration for effects on thestructure and function of the gastric mucosa wasapproximately 1 mmol/liter; (2) the maximum ornear-maximum effects were caused by 10 mmol/liter F; (3) theeffects persisted for at least 6 hr after the exposure;and (4) dmPGE₂ (0.5 μg/ml) did notattenuate the effects induced by F.