成長期顎骨の実験的骨粗鬆症に対するカルシウムの影響に関する研究 : とくに下顎頭の変化
スポンサーリンク
概要
- 論文の詳細を見る
Effects of changes in calcium intake in food on the various functions of a living body have not been clarified in many respects. Three-week old male rats of Wistar strain therefore were given a calcium-deficient diet and osteoporosis was induced in them exper-imentally. The control group was then given a standard diet and the experimental group the mixture of calcium-enriched food. Effects of diet on the mandibular condyle, tibia epiphysis, and tibia metaphysis were investigated. The results were as follows : 1. Radiological findings The mandibular condyle, tibia epiphysis, and tibia metaphysis in the experimental group showed orderly form, widening of dense osseous layers, and increase in and dense running of trabeculae with elapse of experiment weeks as compared with the control group. 2. X-ray microanalytical findings A quantitative analysis, by point analysis, of the distributions of Ca and P was made, and relative quantitative ratios of Ca, (Ca/[Ca]c), and those of P, (P/[P]c), were determined. In the experimental group, Ca/[Ca] c showed high values at the sixth and seventh week, and P/[P] c showed low values at the fifth and sixth week and high values at the seventh week, as compared with the control group. 3. Histopathological findings 1) Contact microradiographic findings i) Granular trabeculae of primary spongiosa in the mandibular condyle in the experimental group decreased with elapse of experiment days, as compared with the control group. Trabeculae of secondary spongiosa increased, widened, and were running densely. ii) As compared with those of the control group, granular trabeculae of primary spongiosa in the tibia epiphysis in the experimental group showed no changes until the fifth week but became narrower and were running densely with elapse of experment days. Trabeculae of secondary spongiosa increased and were running densely. iii) As compared with those of the control group, trabeculae of primary spongiosa in the tibia metaphysis in the experimental group decreased with elapse of experiment days. Trabeculae of secondary spongiosa increased and were running densely. 2) General histologic findings i) As compared with that in the control group, the mandible in the experimental group showed with time a thin cartilage layer due to decrease in hypertrophic chondrocytes, findings of erosion of calcified matrix by chondroclasts, and increase in subchondral bone formation. Scanning electron microscope observation morphologically showed formation of cartilage lacunar walls with vertical matrix, and calcospherites on the lacunar bottom in both the control and experimental groups. Bone lacune were seen in the zone of bone formation, and the opening of bone canalicul us was observed at the bottom. ii) As compared with that in the experimental group, the tibia epiphysis in the control group showed decrease in proliferative chondrocytes and hypertrophic chondrocytes at the fifth week, and a thin cartilage layer due to decrease in hypertrophic chondrocytes at the sixth week and decrease in proliferative chondrocytes at the seventh week. Findings of erosion of calcified matrix by chondroclasts were numerous at the fifth week, but the findings at the sixth and the seventh week were about the same as those of control group. iii) The tibia metaphysis in the experimental group, as compared with that in the control group, showed a thin cartilage layer due to decrease in hypertrophic chondrocytes, and no changes were seen in the cartilage layer at the sixth and the seventh week. Findings of erosion of calcified matrix by chondrocytes and intracatilage bone formation increased with elapse of experiment days. On the basis of the foregoing findings, administration of calcium-enriched food for bone debility has proved to facilitate bone formation in the mandibular condyle, tibia epiphysis, and tibia metaphysis. The effect of calcium on chondrocytes was highest in the mandibular condyle, with the tibia epiphysis and tibia metaphysis following in descending order.
- 九州歯科学会の論文
- 1990-04-25