Histopathological changes in hippocampal CA1 area of rats with coal burning fluorosis

ObjectiveTo duplicate the animal model with coal burning fluorosis and to observe its influence on the histopathology in the hippocampal CA1 area in rats.MethodsTw enty-four SD rats were randomly divided into control, low-fluoride,and high-fluoride exposed groups.Low-and high-fluoride exposed groups were fed with the corn polluted in drying processes with burning coal containing high level of fluoride from the endemic fluorosis area to produce the animal model of fluorosis.During the sixth month experiment,fluoride contents in urine,bone and brain of the rats were detected with fluorine ion selective electrode,and neuro-pathological changes of the hippocampal CA1 area of the rats were examined with hematoxylin-eosin and Nissl's staining and analyzed by Biomias 2000 Imaging Analysis System.ResultsCompared with those of the control group(1.68±0.02 mg/L,1 479±127,0.52±0.05 mg/kg of fluoride contents in urine,bone,and brain tissue),the fluoride contents in urine(2.87±0.12,5.27±0.15 mg/L),bone(2 912±140,4 624±20 mg/kg),and brain tissues(1.14±0.04,1.79±0.04 mg/kg)of the rats with fluorosis were increased markedly with significant differences(P<0.05 or 0.01 for all).The average grey values of neurons in the hippocampal CA1 of the rats were significantly increased in low-fluoride(157±7)and high-fluoride(164±8)exposed groups compared to those of the control(115±4).ConclusionChronic fluorosis could be induced by feeding with corn polluted with high level of fluoride and the fluorosis can decrease protein synthesis in neurons of brains in rats.