The investigation was performed on male Wistar rats 8 weeks old weighing 180 g given sodium fluoride in drinking water at a concentration of 5 and 25 mg F/L for 12 weeks. Control animals received tap water containing 0.3 mg F/L. At the beginning of the experiment and after 2, 4, and 12 weeks of exposure, 6 animals from each group were sacrificed, and samples of blood, liver, kidney, brain, and testis were collected.