抄録
Decreased ovarian function and low calcium intake are major factors of osteoporsis. To know the effect of these factors, following experiments were performed. 24 female Wistar rats were divided into 4 groups: 1st, control group; 2nd low calcium intake group; 3rd, ovariectomized group; 4th, ovariectomized low calcium intake group. Ovariectomy or sham operation was performed at age of 8 weeks. 2 weeks after operation, experimental diets were started. In experimental diets, low calcium diet contained 0.08% calcium, and normal calcium diet contained 0.6% calcium. 5 weeks later, they were sacrificed, and mineralization profile of their right femur was measured. Then, bone histmorphometry of proximal femurs was performed.
At organ, tissue, and BMU levels, both low calcium intake and ovariectomy had the same effects. At organ level, bone mass was decreased. At tissue level, bone turnover was increased. At BMU level, bone formation period relatively elongated than bone resorption period. In either level, low calcicm intake and ovariectomy effected independently and additively. The difference between low calcium intake and ovariectomy was seen in only cell level. The osteoid thickness of ovariectomized groups was thicker than that of control and low calcium intake groups. Osteoblastic disfunction in ovariectomy was considered.
