| chronic dw rat |
Chronic (>90 days) |
The control group was fed with tap water with fluoride concentration less than 0.5 mg/L, while rats in the low and high fluoride dosing groups were fed with tap water with fluoride concentrations at 5.0 and 50.0 mg/L. After 6 months dosing period, rats were selected to participate learning and memory tests which were killed by bleeding through arteria cruralis. Then samples of brains were taken and stored in the temperature -80 °C.; A total of seventy-two SD rats (provided by Guizhou Laboratory Animal Engineering Technology Center), weighing 100 to 120 g, were randomly divided into 3 groups based on body weight and gender, 24 per group (half male and half female). All groups were fed with standard animal food prepared by Guizhou Laboratory Animal Engineering Technology Center (fluoride concentration < 6 mg/kg). |