ABSTRACT
The biological effects of excessive fluoride have been studied at a number of levels of cellular order and complexity in an attempt to understand the metabolic alterations resulting from an increased cellular concentration of fluoride. Several bacterial and mammalian cell lines have been adapted to grow at levels of fluoride normally inhibiting to growth. The cells were incubated in radioactive fluoride and the concentrations calculated from the distribution ratios observed. Cultured mammalian cells offer some advantages in the study of fluoride effects on metabolism. The effects seen are likely to apply to toxicity in intact animals, and many of the problems associated with metabolic studies in intact animals are alleviated. Several amino acids have also been shown to improve the growth of fluoride-treated cells. The observations in bacterial systems demonstrate that organisms can become resistant to the effects of fluoride, and that resistance may develop in different ways.
