Effects of sodium fluoride on HeLa cells: I. Growth sensitivity and adaption

Abstract

Growth of HeLa cells in monolayer cultures was inhibited by fluoride concentrations of 20 ppm or greater and approximately 45 ppm completely eliminated cell growth. Fluoride inhibition of growth was not associated with an altered cell size or a decrease in cell attachment to the culture vessel. The toxicity of fluoride was not markedly altered by changing the calcium and magnesium concentration of the medium, by growth in an atmosphere of 5 per cent CO 2—95 per cent N 2 instead of 5 per cent CO 2—95 per cent air, or by growth in different cell media. Growth inhibition by fluoride was caused by a reduced growth rate which probably resulted from a metabolic defect in these cells. HeLa cells that were exposed to gradually increasing concentrations of fluoride in the medium continued to grow in fluoride concentrations that were at least twice as high as those required for complete inhibition of growth in normal stock cultures.