Introduction:
The fluorine content in food depends on the presence of its compounds in water, soil and air. Owing to the high activity of the fluoride ion and its significant affinity to divalent metals, which are co-factors of many enzymes, changes in the activity of these enzymes may take place, resulting, among other things, in ATP concentration changes and free radical generation. The aim of this work was to assess the effects of length of exposure and fluorine concentration on culture growth, fibroblast energy homeostasis and the production of nitricoxide.

Material and Methods:
The research was conducted on fibroblasts isolated by means of mouse skin tissue explants from the tail and abdomen, BALB/c strain. The culture was bred with added sodium fluoride of final concentration of: 0.03 mmol/l; 0.06 mmol/l and 0.12 mmol/l. The culture growth time was: 1, 3 and 6 days. The culture growth indicator (N/N 0 ) was determined, as well as the ATP concentration and the amount of nitric oxide(II) released into the medium. The results obtained were cal- culated for 1 2 10 6 cells.

Results:
The highest values of the growth indicator, ATP concentration and nitric oxide were found in control cultures. The results obtained suggest that the presence of fluoride ions inhibits fibroblast culture growth, decreases ATP synthesis and lowers nitric oxide(II) production. The changes depend on the concentration of fluoride and the time of cell culture cultivation.

Conclusions:
Long-term exposure even to low fluoride concentrations disturbs cell homeostasis.