直立体位下无创轴向加载建立兔椎间盘退变动物模型

发布时间：2018-06-25 22:04

  本文选题：椎间盘退变 + 动物模型　； 参考：《中国脊柱脊髓杂志》2017年06期

【摘要】：目的:通过直立体位下无创性轴向加载的方式,建立一种新型兔腰椎间盘早期退变的动物模型。方法:24只4月龄雄性新西兰大白兔随机分为实验组及对照组。将实验组动物置于特制筒内使之保持直立体位,并自颈部施以600g轴向载荷,每日6h;对照组动物不接受任何处理而常规饲养。在实验开始前及实验开始后4周、8周、12周时对全部动物行X线及MRI检查,观察实验组动物在筒内时腰椎的骨性结构,通过椎间盘高度指数(disc height index,DHI)测量,比较两组动物侧卧位时L2/3、L4/5和L6/7节段椎间隙高度改变;通过髓核相对灰度值测量比较两组动物髓核含水量变化。14周后全部动物处死,取L5/6节段胶冻状髓核组织,应用rtPCR检测Ⅰ型胶原、Ⅱ型胶原及蛋白多糖表达水平;取L6/7节段椎间盘连同上、下各1mm软骨下骨,应用HE及天狼星红染色观察各组动物椎间盘组织结构改变。结果:2只实验组动物在实验过程中死亡,其对应的实验数据从结果中剔除。腰椎X线片显示,在直立体位负重条件下,实验组兔腰椎形成明显后凸,较侧卧位下腰椎间隙明显变窄,在L2/3节段,直立体位下椎间隙高度为侧卧位时的75.1%(P0.05);在L4/5节段为54.8%(P0.05);在L6/7节段为47.9%(P0.05)。DHI测量显示两组动物腰椎各节段DHI在任何时间点均无显著差异(P0.05)。MRI结果显示,在L2/3节段,实验组与对照组髓核灰度值在任何时间点均无统计学差异(P0.05),在L4/5节段,实验组与对照组髓核相对灰度值在12周时开始具有显著差异(P0.05);在L6/7节段,两组间在8周时即开始有显著性差异(P0.05)。rt-PCR结果显示,实验组Ⅰ型胶原m RNA表达明显高于对照组(3.57倍,P0.05);而Ⅱ型胶原及蛋白多糖表达明显低于对照组(分别为0.35倍和0.43倍,P0.05)。病理学检查显示对照组与实验组椎间盘组织结构存在显著差异,对照组髓核组织与纤维环间边界清晰,髓核内富含均匀分布的髓核细胞;实验组内层纤维环明显增生,而髓核区域相应减小。结论:直立体位下无创性轴向加载方式可显著加速兔腰椎间盘的退变进程,其在发病机理上与人类椎间盘退变更加相似,该腰椎间盘退变动物模型操作简单、可重复性强。
[Abstract]:Aim: to establish a new animal model of early degeneration of lumbar intervertebral disc in rabbits by noninvasive axial loading in upright position. Methods 24 4 month old male New Zealand white rabbits were randomly divided into experimental group and control group. The animals in the experimental group were placed in a special tube and kept upright, and 600g axial load was applied from the neck for 6 hours per day, while the control group was kept without any treatment. X-ray and MRI examinations were performed before the beginning of the experiment and 4 weeks and 8 weeks to 12 weeks after the experiment. The bone structure of the lumbar vertebrae in the experimental group was observed. The disc height index (disc height) was used to measure the bone structure of the lumbar vertebrae. The changes of intervertebral space height in L2 / 3, L4 / 5 and L6 / 7 segments were compared between the two groups, and the changes of water content in the nucleus pulposus of the two groups were compared by measuring the relative gray value of the nucleus pulposus. After 14 weeks, all the animals in the two groups were killed and the gelatinized nucleus pulposus tissues of L5 / 6 segments were taken. The expression levels of collagen type 鈪，

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