抄録
1) From the rabbits injected 45Ca and 32P, various parts of mandible and diaphysis of femur were obtained and the contents of water and organic matters and radioactivties in every bone sample were determined. The diaphysis of femur contained about 10% of water and 26% of organic matters. The alveolar septa contained about 23% of water and 37% of organic matters, and the other parts of mandible contained 11-16% of water and 25-30% of organic matters. The radioactivities of bone reached a maximum at approximately 6 hours after the injection of isotopes and distributed in alveolar septa about twice higher than in the other parts of mandible and diaphysis of femur. The disappearance curves for radioactivities from various parts of bones could be expressed as a series of two exponentials and the curves were almost parallel in each sample. 2) After the administration of 45Ca and 32P the femur, mandible and vertebra were obtained and they were powdered and fractionated by Manly-Hodge’S floatation method. The heavier fractions contained less organic matters but the specific gravities of these fractions were not proportional to organic contents. The specific activities of 1.9-2.0 fraction from mandible and femur were about 10 times higher than those of 2.1-2.2 fraction and 3-4 times higher than those of 2.0-2.l fraction. On the other hand the specific activities of each fraction from vertebra showed less activities than those fraction obtained from femur and mandible, and the specific activities in 1.9-2.0 fraction obtained from vertebra were about twice higher than those of 2.0-2.l fraction. The disappearance curves for radioactivities from each fraction were almost parallel. 3) The fractionated bone powders were extracted by ethylene diamine to remove the organic matters and each extracted bone Sample was used for X-ray diffraction studies. From the data of X-ray diffraction and low angle X-ray scattering, it seemed that the size of crystal in every bone fraction was in order of the specific gravity 2.1-2.2, 2.0-2.1 and 1.9-2.0 fraction according to largeness and in the same specific gravity fraction the size of crystal was in order of the femur, mandible and vertebra.
