Katsumata T, Nakamura T, Ohnishi H, Sakurama T
Sumitomo Pharmaceuticals Research Center, Osaka, Japan.
J Bone Miner Res. 1995 Jun;10(6):921-31. doi: 10.1002/jbmr.5650100613.
We examined the mechanical properties of rat bones treated with etidronate intermittent cyclic treatment (etidronate-ICT). Fifty Fisher rats, 7 months of age, underwent ovariectomy (OVX; n = 40) or sham operation (n = 10). The OVX rats were assigned to 4 groups injected with etidronate at the respective dose of 0, 2, 4, or 8 mg/kg of body weight (bw) 5 days each week for 2 weeks, followed by a 10-week period of no treatment. This regimen was repeated for 48 weeks. At the end of the treatment period, the ultimate bending strength and structural stiffness of the femoral midshaft in the OVX-alone group were not reduced compared with the values of the sham group, while those in the etidronate-treated groups were significantly larger than the values of the OVX group. The compressive stiffness and strength of the vertebral bodies specimens prepared from L3 and L5 vertebrae were markedly decreased in the OVX group compared with those in the sham group, but the values in the etidronate-treated groups were maintained at the same levels as those in the sham group. Mechanical properties at the tissue level, such as elastic modulus and material strength of the femoral cortex, were increased in etidronate-treated groups compared with the OVX group. The flexural modulus was also increased. The compressive elastic modulus of vertebral body in treated groups was preserved at the same level as that in the sham group. These results clearly demonstrate that in ovariectomized rats long-term etidronate intermittent cyclic treatment preserves the mechanical properties both at the whole bone and the tissue level.
我们研究了依替膦酸间歇循环治疗（依替膦酸 - ICT）处理的大鼠骨骼的力学性能。五十只7个月大的Fisher大鼠接受了卵巢切除术（OVX；n = 40）或假手术（n = 10）。OVX大鼠被分为4组，每组每周5天分别注射0、2、4或8mg/kg体重（bw）的依替膦酸，共2周，随后为10周的无治疗期。此方案重复48周。在治疗期结束时，仅接受OVX的组中股骨干中段的极限弯曲强度和结构刚度与假手术组的值相比没有降低，而依替膦酸治疗组的这些值明显大于OVX组的值。与假手术组相比，OVX组中由L3和L5椎体制备的椎体标本的压缩刚度和强度明显降低，但依替膦酸治疗组的值维持在与假手术组相同的水平。与OVX组相比，依替膦酸治疗组中股骨皮质的弹性模量和材料强度等组织水平的力学性能有所增加。弯曲模量也增加。治疗组中椎体的压缩弹性模量保持在与假手术组相同的水平。这些结果清楚地表明，在去卵巢大鼠中，长期依替膦酸间歇循环治疗在全骨和组织水平均能保持力学性能。
