Effects of fluoride on locomotion of human blood leucocytes in vitro

The effect of NaF on the locomotion and chemotaxis of human blood neutrophils and monocytes was studied using two assays: the micropore filter assay and a time-lapse cinematographic assay in which the chemotaxis of cells in response to spores of Candida albicans was filmed. At high concentrations (greater than 10(-4) M), NaF inhibited locomotion of both cell types, but no inhibition of locomotion of either cell-type was seen in either assay using NaF at less than or equal to 10(-4) M, whether or not the cells were responding to a chemotactic source. This was so, even for monocytes incubated for 48 h in the presence of NaF. It is therefore improbable that fluoride, at levels added to drinking water or found in the body fluids of persons drinking fluoridated water, has any deleterious effect on the locomotor capacity of phagocytic cells or on their capacity to detect and home on to chemotactic sources.