Yeh J K, Aloia J F, Tierney J M, Sprintz S
Department of Medicine, Winthrop-University Hospital, Mineola, New York 11501.
Calcif Tissue Int. 1993 Mar;52(3):234-8. doi: 10.1007/BF00298725.
Dual energy X-ray absorptiometry (DXA; Hologic QDR-1000W) in an ultrahigh-resolution mode, was used to examine the changes in tibial/fibula and vertebral L4 + L5 bone mineral content (BMC) and bone mineral density (BMD) in each 14-month-old female rat at 0, 9, and 16 weeks of study. Twenty rats were randomized by a stratified weight method into two groups, control and exercised. Exercise consisted of running on a flat-bed treadmill, 17 m/minute, 1 hour/day and 5 days/week. As compared with the control group, a significant increase in tibia/fibula BMC and vertebral BMD was apparent at 9 weeks after exercise training (P = 0.014 by 2-way analysis of variance). The slope of the gain of the tibia/fibula BMC and BMD by 16 weeks of training was ninefold and fivefold higher than that of the control group (P < 0.01 and P < 0.05, respectively, by Mann-Whitney test). The correlation coefficient (r) between the final dry weight of excised bone and the final BMC of the intact rat was 0.843 and 0.71 for tibia/fibula and vertebrae, respectively. In summary, we found that in the aged rat, by 9 weeks, exercise increases BMC and BMD in the tibia, whereas in the vertebrae, only increases in the BMD were found. This study demonstrates that this precise and accurate DXA technique is useful in a longitudinal study of in vivo bone mineral changes in the rat over time by taking into account the individual variation between animals as well as changes between groups.
采用双能X线吸收法（DXA；Hologic QDR - 1000W）的超高分辨率模式，检测每组14月龄雌性大鼠在研究的0、9和16周时胫腓骨及腰椎L4 + L5的骨矿物质含量（BMC）和骨矿物质密度（BMD）变化。20只大鼠通过分层体重法随机分为两组，即对照组和运动组。运动方式为在平板跑步机上跑步，速度为17米/分钟，每天1小时，每周5天。与对照组相比，运动训练9周后胫腓骨BMC和椎体BMD显著增加（双向方差分析，P = 0.014）。训练16周时，胫腓骨BMC和BMD增加的斜率分别比对照组高9倍和5倍（曼 - 惠特尼检验，P分别< 0.01和P < 0.05）。切除骨的最终干重与完整大鼠最终BMC之间的相关系数（r），胫腓骨和椎体分别为0.843和0.71。总之，我们发现，在老年大鼠中，运动9周后可增加胫骨的BMC和BMD，而在椎体中，仅发现BMD增加。本研究表明，这种精确且准确的DXA技术在纵向研究大鼠体内随时间变化的骨矿物质变化时非常有用，因为它考虑了动物个体间的差异以及组间变化。
