Yamauchi H, Kushida K, Yamazaki K, Inoue T
Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Japan.
J Bone Miner Res. 1995 Jul;10(7):1033-9. doi: 10.1002/jbmr.5650100707.
Measurements of lumbar spine (L1-L6) bone mineral density (BMD) and bone mineral content (BMC) of Wistar rats were obtained by dual energy X-ray absorptiometry (DXA) (QDR-1000W, Hologic Inc., Waltham, MA) to estimate reproducibility and investigate age-related changes. In addition we evaluated the accuracy of the technique in female rats. The coefficients of variation (CV) for spine BMD measurements were found to range from 0.73-1.04 in vivo and from 0.36-1.56 in vitro. The in vitro measurements were performed in a 3 cm deep water bath to stimulate an equivalent tissue thickness. Spine BMC, measured in vivo and in vitro correlated closely with the subsequently determined ash weights (r2 = 0.87 and 0.97, respectively). We examined age-related spine BMD by DXA. A relatively constant increase in spine BMD was observed from 6 weeks to 22 weeks; spine BMD remained stable between 22 and 58 weeks. No peak was observed in spine BMD. To evaluate the effect of estrogen deficiency on animals of different ages, we measured spine BMD weekly in female rats subjected to ovariectomy (OVX) or sham operation at 8 and 23 weeks of age. The spine BMDs in each OVX rat were significantly lower than that of the controls. In the 23-week-old rats, bone loss was quite rapid for the first 3 weeks of observation and stable afterward. The BMD of 8-week-old OVX rats increased with body size. We conclude that DXA allows the observation of age-related changes in the spine BMD of rats with great precision.(ABSTRACT TRUNCATED AT 250 WORDS)
通过双能X线吸收法（DXA）（QDR - 1000W，Hologic公司，马萨诸塞州沃尔瑟姆）测量Wistar大鼠腰椎（L1 - L6）的骨密度（BMD）和骨矿物质含量（BMC），以评估其可重复性并研究年龄相关变化。此外，我们评估了该技术在雌性大鼠中的准确性。发现脊柱BMD测量的变异系数（CV）在体内为0.73 - 1.04，在体外为0.36 - 1.56。体外测量在3厘米深的水浴中进行，以模拟等效的组织厚度。体内和体外测量的脊柱BMC与随后测定的灰重密切相关（r2分别为0.87和0.97）。我们通过DXA检查了与年龄相关的脊柱BMD。从6周到22周观察到脊柱BMD相对持续增加；在22至58周之间脊柱BMD保持稳定。未观察到脊柱BMD的峰值。为了评估雌激素缺乏对不同年龄动物的影响，我们在8周和23周龄接受卵巢切除术（OVX）或假手术的雌性大鼠中每周测量脊柱BMD。每只OVX大鼠的脊柱BMD均显著低于对照组。在23周龄的大鼠中，观察的前3周骨丢失相当迅速，之后保持稳定。8周龄OVX大鼠的BMD随体型增加。我们得出结论，DXA能够非常精确地观察大鼠脊柱BMD的年龄相关变化。（摘要截短为250字）
