成長期下顎頭の骨基質形成に関する X 線的, 光顕的および超微形態的研究 : 高タンパク食の影響

Abstract

Male Wistar rats, 3-week-old corresponding to the human weaning period, were used and the effect of high calcium diet intake on bone formation in the mandibular condyle at the growing stage was investigated. The results were as follows : 1. X-ray findings on bone density Significant differences in bone density were found among the control, calcium-deficient diet, and low calcium diet groups with 1% significance level and the control group showed high values. 2. Analytical findings on the X-ray microanalyzer As compared with the control group, relative Ca ratios and relative P ratios were in order of the control group>high protein group>calcium-deficient diet group>calcium-deficient diet + high protein diet group. 3. Histopathological findings As comapred with the control group, the high protein diet group showed increase in hypertrophic chondrocytes, decrease in calcified matrices, and decrease in chondric ossifiction. In the calcium-deficient diet + high protein diet group, chondric ossification was decreased, and as compared with the calcium-deficient diet group, trabeculae were thin and low calcified layers were increased. 4. Scanning electron microscopic findings As compared with the control group, the high protein diet group showed relatively abundant collagen fibrils and indistinct borders of bone resorption surfaces. In the calcium-deficient diet + high protein diet group, as compared with the calcium-deficient diet group, calcified globules were few, coalescence was incomplete, and trabeculae showed marked bone resorption. On the basis of the foregoing findings, administration of high protein diet facilitates pinocytes for formation of bone matrices. From this, it is clear that decrease in and thinning of bone occur for the bone with calcium insufficiency.