カルチトニンの成長期顎骨に及ぼす影響に関する実験的研究 : とくに歯槽骨の変化

Abstract

Three-week-old male rats of Wistar strain were given 0.2u/kg of calcitonin (eel calcitonin) and its effect on the alveolar bone and tibia after administration was investigated. The results were as follows : 1. The control and experimental groups showed increase in weight with time from the first week, but from the third week, increase was greater in the experimental group. 2. Optically, the densitometric curves of the alveolar bone of the experimental group showed higher patterns than thoes of the control group until the fourth week. In the fifth week, however, density curves with ragged undulation were seen. For the tibia, the densitometric curves of interosseous cortex and medial cortex were higher than those for the control group until the fourth week but showed ragged irregular patterns in the fifth week. 3. On the X-ray microanalyzer, in percentages of the averages of Ca and P for the control group, Ca was the highest in the fifth week and P was the highest in the third week, and both were the lowest in the fourth week. For the experimental group, the percentages of both Ca and P were the lowest in the third week and the highest in the fifth week. In standard deviation, increase and decrease in Ca and P in the control and experimental groups occurred in linkage. For the tibia, percentages of the averages of Ca and P in the control and experimental groups showed increase and decrease in linkage and the standard deviation was always smaller for the control group than for the experimental group. The average and standard deviation of P were not linked. 4. Histopathologically, the experimental group, in comparison with the control group, showed a thicker and more compact osseous layer in the alveolar bone and increase in Haversian canals and bone lacunae until the fourth week. However, no osteoclasts were observed. In the fifth week, bone lacunae in the alveolar bone in the experimental group became fewer and many findings of bone resorption by osteoclasts were observed. In the tibia, the experimental group showed more increase in Haversian canals and bone lacunae until the fifth week, as compared with the control group. In the fifth week osteoclasts appeared and bone resorption was observed. Under the scanning electron microscope, collagen fibrils in the experimental group were arranged more compactly irrespective of increase or decrease in the bone tissue. 5. Hemologically, serum Ca in the experimental group was higher than that in the control group in the third week, In the fifth week, serums Ca and CT in the experimental group were higher than those in the control group.