【Animal modeling】-Comparative study on bone growth in rats after long-term exposure to low-fluoride aluminum and short-term high-fluoride aluminum exposure

  OBJECTIVE: To observe the effects of different doses of fluoride and aluminum combined with the duration of intake on longitudinal bone growth and bone metabolism in rats.

  Methods: Forty-eight 8-week-old clean-grade SD rats weighing 170-190 g were randomly divided into normal control, low-fluoride aluminum and high-fluoride aluminum groups, and 45d and 90d groups were set respectively. Proximal tibial growth plate and metaphyseal loosening were performed. Bone morphometry analysis of solid bone.

  Results: Compared with the normal group, the growth plate in the high fluoride aluminum group was thickened, the chondrocytes in the 45 d group were clear, neatly arranged, and had no abnormal shape, while the 90 d group chondrocytes were crowded and retained; The mineralization perimeter, bone formation rate, and osteoblast perimeter of the end-secondary trabecular bone increased, and the bone resorption perimeter increased in the 90-day group; the above-mentioned bone metabolism indexes were increased in the high-fluoride aluminum 45-day group and decreased in the 90-day group. .

  Conclusion: Short-term exposure to high-fluoride aluminum stimulates cartilage growth and long-term inhibits longitudinal bone growth. Short-term exposure to low-fluoride aluminum only increases secondary trabecular bone formation, and both long-term and high-fluoride aluminum exposures can stimulate trabecular bone formation and increase Bone resorption, high fluoride aluminum inhibits bone formation and resorption for a long time.