Zhang Yongqiang, Li Yongfeng, Gao Qi, Shao Bo, Xiao Jianrui, Zhou Hong, Niu Qiang, Shen Mingming, Liu Baolin, Hu Kaijin, Kong Liang
State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University, Xi'an 710032, PR China.
State Key Laboratory of Military Stomatology, Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, Shaanxi, China.
Arch Oral Biol. 2014 Jul;59(7):663-9. doi: 10.1016/j.archoralbio.2014.03.013. Epub 2014 Apr 2.
This study aimed to compare the variation of cancellous bones at four skeletal sites: lumbar vertebra, femoral neck, mandibular angle and rib in ovariectomized sheep. Sixteen adult sheep were randomly divided into two groups: eight sheep were ovariectomized served as experimental group; the other eight untreated sheep were served as control group. Bone mineral density was assessed by dual-energy X-ray absorptiometry on lumbar vertebrae at baseline and twelve months after ovariectomy. After 12 months, lumbar vertebrae L3 and L4, femoral necks, mandibular angles and the fourth ribs were harvested for micro-CT scanning, histological analysis and biomechanical test. The results showed that bone mineral density of lumbar vertebra decreased significantly in twelfth month (p<0.05). The results of micro-CT showed that the bone volume/total volume decreased by 45.6%, 36.1% 21.3% and 18.7% in lumbar vertebrae, femoral necks, mandibular angles and ribs in experimental group (p<0.05) respectively. The trabecular number showed the same downtrend (p<0.05). Histological analysis showed trabecular area/tissue area decreased by 32.1%, 23.2% and 20.7% in lumbar vertebrae, femoral necks and mandibular angles respectively (p<0.05), but no significant difference in ribs. Specimens elastic modulus from lumbar vertebra, femoral neck and mandibular angle were 952±76MPa (628±70MPa), 961±173MPa (610±72MPa) and 595±60MPa (444±31MPa) in control group (experimental group) respectively. These datum indicated that the sensibility of cancellous bones to oestrogen deficiency in ovariectomized sheep was site-specific on a pattern as follows: lumbar vertebra, femoral neck, mandibular angle and rib.
本研究旨在比较去卵巢绵羊腰椎、股骨颈、下颌角和肋骨这四个骨骼部位松质骨的变化。16只成年绵羊随机分为两组：8只绵羊接受去卵巢手术作为实验组；另外8只未处理的绵羊作为对照组。在基线时以及去卵巢术后12个月，通过双能X线吸收法评估腰椎的骨密度。12个月后，采集L3和L4腰椎、股骨颈、下颌角以及第四肋骨进行显微CT扫描、组织学分析和生物力学测试。结果显示，腰椎的骨密度在第12个月时显著降低（p<0.05）。显微CT结果显示，实验组腰椎、股骨颈、下颌角和肋骨的骨体积/总体积分别下降了45.6%、36.1%、21.3%和18.7%（p<0.05）。骨小梁数量呈现相同的下降趋势（p<0.05）。组织学分析显示，腰椎、股骨颈和下颌角的骨小梁面积/组织面积分别下降了32.1%、23.2%和20.7%（p<0.05），但肋骨无显著差异。对照组（实验组）腰椎、股骨颈和下颌角标本的弹性模量分别为952±76MPa（628±70MPa）、961±173MPa（610±72MPa）和595±60MPa（444±31MPa）。这些数据表明，去卵巢绵羊的松质骨对雌激素缺乏的敏感性具有部位特异性，模式如下：腰椎、股骨颈、下颌角和肋骨。
