Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
Spine (Phila Pa 1976). 2009 Oct 15;34(22):2363-8. doi: 10.1097/BRS.0b013e3181b04e52.
Animal experiment using a rabbit posterolateral intertransverse process fusion model.
To explore the temporal and spatial distribution of sensory nerve fibers expressing calcitonin-gene related peptide (CGRP) during spinal fusion induced by recombinant human bone morphogenetic protein-4 and the role of the CGRP innervation in ectopic bone formation and remodeling.
Sensory neuropeptide CGRP involved in local bone turnover has been evidenced but its underlying mechanism is poorly understood. Knowledge in the CGRP innervation in ectopic bone induced by bone morphogenetic proteins can help us to understand its role in bone turnover.
Twenty-seven New Zealand white rabbits underwent single level posterolateral intertransverse process fusion of the lumbar vertebrae with implantation of porous poly-d,l-lactic acid blocks loaded with 1.25 microg recombinant human bone morphogenetic protein-4 solution. Animals were killed and the operated lumbar vertebrae were harvested for histomorphological evaluation at 3 days (n = 3), 1 week (n = 6), 3 weeks (n = 6), 7 weeks (n = 6), and 12 weeks (n = 6) following surgery, respectively.
New cartilage presented at 1 week postimplantation adjacent to the implant, reached a peak volume at week 3 followed by a drop till week 12 after its ossification. Trabeculae-like woven bone structure presented at week 3. CGRP-positive nerve fibers regenerated already at 3 days postimplantation, reached its peak density at week 3. The CGRP-positive fibers presented both in fibrous tissues adjacent to proliferating cartilages and in bone marrow of newly formed trabecular bone.
The observed spatial and temporal regeneration of CGRP-positive nerve fibers in ectopic bone formation suggested CGRP innervation is associated with ectopic osteogenesis.
使用兔后外侧横突间融合模型的动物实验。
探讨在重组人骨形态发生蛋白-4诱导的脊柱融合过程中，感觉神经纤维表达降钙素基因相关肽（CGRP）的时空分布，以及 CGRP 神经支配在异位骨形成和重塑中的作用。
涉及局部骨转换的感觉神经肽 CGRP 已得到证实，但作用机制尚不清楚。了解骨形态发生蛋白诱导的异位骨中 CGRP 神经支配有助于我们了解其在骨转换中的作用。
27 只新西兰白兔行单节段腰椎后外侧横突间融合术，植入负载 1.25μg 重组人骨形态发生蛋白-4溶液的多孔聚-d,l-乳酸块。术后 3 天（n = 3）、1 周（n = 6）、3 周（n = 6）、7 周（n = 6）和 12 周（n = 6）处死动物并采集手术部位腰椎进行组织形态学评估。
植入后 1 周可见新生软骨紧邻植入物，3 周时达到峰值体积，随后在 12 周时下降。3 周时出现小梁样编织骨结构。植入后 3 天 CGRP 阳性神经纤维开始再生，3 周时达到高峰密度。CGRP 阳性纤维存在于增殖软骨旁的纤维组织中和新形成的小梁骨骨髓中。
在异位骨形成中观察到 CGRP 阳性神经纤维的空间和时间再生表明 CGRP 神经支配与异位成骨有关。
