칼시토닌 고분자 미립자 투여에 따른 골다공증 유발 쥐의 골밀도 변화

Change of Bone Mass Density as Injection of Calcitonin-microsphere in Osteoporosis-Induced Rats

Objective: To evaluate bone protective effects of salmon calcitonin microspheres against cancellous bone loss in ovariectomized rats. Method: Thirty five osteoporosis-induced Sprague-Dawley rats were randomly divided into five groups (high dose calcitonin group (112 U/kg), low dose calcitonin group (56 U/kg), free calcitonin group, only ovariectomy group, control group). Ovariectomized rats were injected s.c. with salmon calcitonin microspheres(l12 U/kg or 56 U/kg) weekly, and free salmon calcitonin on alternate days. control rats and the remaining ovariectomized rats were injected s.c. on alternate days with saline vehicle. The effects and side effects in each group were assessed by the bone mineral density and bone histomorphomeσy. Results: 1. At four months after the ovariectomy, the bone mineral densities in high dose calcitonin group were 0.1640±0.0156 grn/㎠, the bone mineral densities in low dose calcitonin group were 0.1600±0.0114 gm/㎠, the bone mineral densities in calcitonin group were 0.1531±0.0168 gm/㎠, the bone mineral densities in ovariectomy group were 0.1404±0.0070 gm/㎠, the bone mineral densities in control group were 0.1896±0.0163 gm/㎠. The bone mineral densities of the femur in ovrariectomy groups compared with control group were decreased with time. The difference of the bone mineral densities between high and low dose calcitonin group and ovariectomy groups was significant (p<0.05). 2. We found that the bone trabeculi in bone histomophometry were more maintained in high dose calcitonin group compared with ovariectomy group. Conclusion: 1. Bone mineral densities of salmon calcitonin microsphere injected rats was higher than only ovariectomized rats in femur. 2. Bone mineral densities of salmon calcitonin microsphere injected rats had no significant differences than only ovariectomized rats in L5 vertebra. 3. In histologic examination, salmon calcitonin microsphere and free salmon calcitonin injected rats showed more prominent bony trabeculae than ovariectomized rats.