Effect of fluoride on uptake of D-glucose by isolated epithelial cells of rat intestine.

Inhibition on uptake of D-glucose by isolated intestinal epithelial cells (IIEC) was observed when the fluoride concentration ranged between 0.25 and 5 mM. Active transport was almost completely inhibited at 5 mM. When CaCl2 was added to fluoride, the inhibitory effect on glucose uptake was abolished. Preincubation of IIEC with different concentrations of fluoride (2.5-5.0 mM) for different intervals of time (2-20 min) at different pH levels (6.2-7.8) and temperatures (0-37 degrees C) revealed that the conditions which led to higher uptake of fluoride by IIEC produced maximum inhibition. The degree of inhibition was not appreciably altered by a change in glucose concentrations. A concentration-dependent effect of fluoride on lactic acid and carbon dioxide production by IIEC was also observed.