Ferguson V L, Greenberg A R, Bateman T A, Ayers R A, Simske S J
Departments of Mechanical, University of Colorado at Boulder, USA.
Biomed Sci Instrum. 1999;35:85-91.
While caloric restriction is a proven means to extend longevity, its effects on bone are not well understood. This study examined the effects of dietary restriction without vitamin or mineral supplementation on bone in female 60- and 120-day-old C57BL/6J mice. Baseline controls were sacrificed at 60 or 120 days, while diet-restricted animals ate approximately 72.9-78.6% of the ad libitum fed animals for thirty days. 60-day-old ad libitum animals experienced normal growth with average increases of 6.4% in bone length, 23.5% in bone mass, 9.4% in %mineralization, 36.4% in maximum strength, 59.2% in stiffness, 22.3% in cortical thickness, 12.9% in %cortical area, and 11.3% in microhardness. Growth in 120-day-old ad libitum animals followed a trend but with more modest increases. Diet-restricted mice matured very little from baseline levels in 60-day-old animals. There were no significant changes from baseline levels in the parameters indicated above, except for a 8.3% decrease in %cortical area attributable to increased resorption. 120-day-old diet-restricted animals also evidenced little deviation from baseline levels except for significant decreases in %mineralization (2.1%) and %cortical area (6.7%). The effects of diet restriction on bone properties decreased with age. Bone from 60-day-old diet-restricted mice showed diminished mechanical and compositional properties, resulting from little growth and excess resorption. Bone from 120-day-old diet-restricted mice showed little growth and some resorption. Increased resorption, localized on the endosteal surfaces, likely minimized the negative impact of structural degradation of the long bones. Resorption may have also provided minerals to compensate for nutritional deficiencies.
虽然热量限制是延长寿命的一种已被证实的方法，但其对骨骼的影响尚未得到充分了解。本研究考察了在不补充维生素或矿物质的情况下，饮食限制对60日龄和120日龄雌性C57BL/6J小鼠骨骼的影响。在60天或120天时处死基线对照组，而饮食限制组动物在30天内进食量约为自由进食动物的72.9 - 78.6%。60日龄自由进食动物生长正常，骨长度平均增加6.4%，骨量增加23.5%，矿化百分比增加9.4%，最大强度增加36.4%，硬度增加59.2%，皮质厚度增加22.3%，皮质面积百分比增加12.9%，显微硬度增加11.3%。120日龄自由进食动物的生长呈一定趋势，但增加幅度较小。饮食限制的60日龄小鼠与基线水平相比成熟度很低。除了由于吸收增加导致皮质面积百分比下降8.3%外，上述参数与基线水平无显著变化。120日龄饮食限制动物与基线水平相比也几乎没有偏差，只是矿化百分比（2.1%）和皮质面积百分比（6.7%）显著下降。饮食限制对骨骼特性的影响随年龄增长而降低。60日龄饮食限制小鼠的骨骼显示出力学和成分特性减弱，这是由于生长不足和吸收过多所致。120日龄饮食限制小鼠的骨骼生长很少且有一些吸收。内骨膜表面吸收增加可能最大限度地减少了长骨结构退化的负面影响。吸收也可能提供了矿物质以弥补营养缺乏。
