DISTRIBUTION PROFILES OF FLUORIDE IN 3 DIFFERENT KINDS OF RAT BONES

The study was performed to reveal the detailed distribution profiles o f fluoride in three different kinds of rat bone-humerus, vertebral arc h, and parietal bone-and to compare this with the histological appeara nce of each bone type. Two groups of Wistar rats were provided water a d libitum containing 0 and 100 ppm fluoride, respectively, for 24 week s. The fluoride distribution profiles across the bone of the three dif ferent bones from the outer to the inner surface were determined by me ans of an abrasive micro-sampling technique. In control animals, both humerus and parietal bones showed higher concentrations at the periost eal and endosteal surfaces, while the vertebral arch showed additional high levels in the middle (containing trabecular bone) of the tissue. In exposed animals, fluoride levels increased greatly in all three bo ne types. The vertebral and parietal fluoride distribution profiles we re relatively unchanged, although humerus fluoride increased from peri osteum to endosteum. The differences in fluoride distribution profiles were apparently related to the histological appearances of these bone s. The surface area of bone available and the extent of vascularity ap pear to affect fluoride uptake.