Iwamoto Jun, Matsumoto Hideo, Takeda Tsuyoshi, Sato Yoshihiro, Xu Edward, Yeh James K
Department of Sports Medicine, Keio University School of Medicine 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Chin J Physiol. 2008 Dec 31;51(6):331-7.
The purpose of the present study was to compare the effects of alendronate (ALN) and alfacalcidol (ALF) on the femoral bone mass and bone strength in orchidectomized rats and to clarify the skeletal benefits of combined administration of ALN and ALF. Fifty male Sprague-Dawley rats, 3 months of age, were randomized by the stratified weight method into five groups: the age-matched control (CON), orchidectomy (ORX), ORX + ALN (2.5 microg/kg, s.c., 5 times a week), ORX + ALF (0.1 microg/kg, p.o., 5 times a week), and ORX + ALN + ALF groups. After 12 weeks of feeding, the femoral distal metaphysis and mid-diaphysis were processed for peripheral quantitative tomographic analysis and biomechanical testing. In the femoral distal metaphysis, ALN prevented the ORX-induced reduction in the trabecular volumetric bone mineral density (vBMD) and breaking energy, and ALF prevented the ORX-induced reduction in the trabecular vBMD and increased the breaking energy to values above those observed in the CON group. Both ALN and ALF increased the maximum load to values above those observed in the ORX group. The improvements in parameters described above were more pronounced when ALN and ALF were administered in combination. In the femoral mid-diaphysis, on the other hand, ALN did not significantly affect the cortical bone parameters, whereas ALF increased the cortical area and maximum load to values above those observed in the ORX group. Furthermore, no apparent benefit of combined administration of ALN and ALF was observed. These findings suggest differential effects of ALN and ALF on femoral bone mass and the beneficial effects of combined administration of ALN and ALF on the trabecular bone of the femur in ORX rats.
本研究的目的是比较阿仑膦酸盐（ALN）和阿法骨化醇（ALF）对去势大鼠股骨骨量和骨强度的影响，并阐明ALN和ALF联合给药对骨骼的益处。将50只3月龄雄性Sprague-Dawley大鼠按分层体重法随机分为五组：年龄匹配对照组（CON）、去势组（ORX）、ORX + ALN组（2.5微克/千克，皮下注射，每周5次）、ORX + ALF组（0.1微克/千克，口服，每周5次）和ORX + ALN + ALF组。喂养12周后，对股骨远端干骺端和骨干中部进行外周定量断层分析和生物力学测试。在股骨远端干骺端，ALN可防止ORX诱导的小梁体积骨密度（vBMD）和断裂能量降低，ALF可防止ORX诱导的小梁vBMD降低，并使断裂能量增加至高于CON组的值。ALN和ALF均使最大负荷增加至高于ORX组的值。当联合使用ALN和ALF时，上述参数的改善更为明显。另一方面，在股骨骨干中部，ALN对皮质骨参数无显著影响，而ALF可使皮质面积和最大负荷增加至高于ORX组的值。此外，未观察到ALN和ALF联合给药有明显益处。这些发现提示ALN和ALF对股骨骨量有不同影响，且ALN和ALF联合给药对去势大鼠股骨小梁骨有益。
