This study was designed to test the effect of natural
calcium on the bone loss induced by
ovariectomy in rats. Thirty female four-month rats were divided into three groups:
sham operated group (
Sham), ovariectomized group (OVX) and ovariectomized with
calcium supplementation group (OVX + CA). OVX + CA rats were treated with
calcium at a dose of 50 mg/kg weight per day for 90 days after surgery. Blood biochemical analysis, bone pathology, bone histomorphometric measurement and bone weight were processed. OVX rats were characterized by thinning, wormerosion like loss of trabecular bones, decreased volume of cancellous bone, increases in osteoblast index and osteoclast index, decreases in wet, dry and ash weights of left femur, and decreases in contents of
calcium and
phosphorus of bones. Treatment of OVX + p6 rats with
calcium provided complete protection against bone loss and significantly depressed bone turnover. Our results indicate that natural
calcium is effective in prevention of
osteopenia in ovariectomized rats. The authors believe that the main mechanism of
calcium against bone loss exists in correction of minus
calcium balance, and depression of high bone turnover, especially the absorption action of osteoclasts.