绝经后骨质疏松模型兔骨髓脂肪酸成分变化规律  

MR Spectroscopy Evaluation of Marrow Fatty Acid Composition in the Ovariectomized Rabbit

作　　者：李冠武[1] 常时新[1] 秦玲娣[1] 田芳[1] 薛峰[1] 周蕾[1] 周自明[1] 

机构地区：[1]上海中医药大学附属岳阳中西医结合医院医学影像科,200437

出　　处：《临床放射学杂志》2014年第3期451-455,共5页Journal of Clinical Radiology

基　　金：国家自然科学基金资助项目(编号:81202809;81373856)

摘　　要：目的 探讨绝经后骨质疏松（PMOP）模型兔骨髓脂肪酸成分变化规律。方法12只5月龄雌性新西兰大白兔随机分为假手术（SHAM）及去势（OVX）组（n=6／组）。分别在基线及术后3、6个月行磁共振波谱（MRS）及骨密度（BMD）扫描测定骨髓饱和脂质含量（SLC）及不饱和脂质指数（ULI）、BMD。离体L。及左侧股骨生物力学测试。结果OVX后SLC呈显著性增高而ULI逐渐降低，术后3个月SHAM及OVX组SLC分别为（34．0±5．7）％、（41．74±7．2）％，差异有统计学意义（P〈0．05），而组间ULI至术后6个月才有显著性差异。术后3、6个月OVX组SLC较基线分别增高27．1％、63．4％，而ULI较基线分别降低18．2％、32．3％。OVX组BMD呈渐进性降低，至术后6个月组间BMD差异有统计学意义（P〈0．05）。OVX组术后6个月L_3～L_4及股骨近端BMD分别较基线降低21．5％、14．1％，L_4最大抗压缩载荷及抗压缩强度较SHAM组分别降低48．9％、49．0％，而股骨最大抗弯曲载荷及弹性模量较SHAM组分别降低16．4％、20．5％（P均〈0．05）。L_3～L_4及股骨BMD与SLC值负相关（r分别为-0．570、-0．672，P均〈0．01），而与ULI值存在正相关（r分别为0．506、0．613，P均〈0．05）。结论PMOP骨受损伴随着骨髓饱和脂质增多而不饱和脂质降低，MRS可动态评价骨髓脂质成分。Objective To explore the effect of estrogen deficiency on marrow fatty acid composition in a rabbit model assessed by proton MR spectroscopy （MRS）. Methods Twelve 20 weeks old female rabbits were randomly assigned to sham operation （SHAM） and ovariectomy （OVX） group （n = 6 per group）. Marrow fatty acid composition and bone mineral density （BMD） at the left proximal femur and L3 - L4 vertebrae were measured by MRS and Dual energy X ray absorptiometry at 0, 3 and 6 monthes. Biomechanical strength was assessed at month 6. Results The OVX rabbits showed a significant increase in SLC and a reduction in ULI over time, with a SLC variation （ ＋ 27.1% at month 3 and ＋ 63.4% at month 6） and a ULI variation （ - 18.2% and -32.3% ） with respect to baseline. The OVX group demonstrated significant bone loss first detected at month 6, followed by increased SLC first detected at month 3 and decreased ULI first detected at month 6 compared with the SHAM group （P 〈 0.05 for all）. In contrast to the SHAM rabbits at month 6, maximum load and strength of anticompression at the L4 vertebra decreased by 48.9% and 49.0% while maximum load of antibending and elasticity modulus at the left femur decreased by 16.4% and 20.5% in the OVX group respectively. BMD values at both the L3 -L4 and proximal femur were negatively related to SLC （r = -0. 570 and r = -0. 672, P 〈 0.01 for all ） while positively associated with ULI （ r = 0. 506 and r = 0. 613, P 〈 0.05 for all）. Conclusion Postmenopausal osteoporosis is characterized by the deterioration of bone and a significant increase in the marrow saturated fatty acid while reduction in the marrow unsaturated fatty acid. MRS appears to be a valuable technique to detect the marrow fatty acid composition.

关 键 词：雌激素 骨质疏松 骨髓脂肪 不饱和脂肪酸 

分 类 号：R580[医药卫生—内分泌]