The Long-Lasting Pattern of the Neuropathic Radicular Pain in An Autologous Nucleus Pulposus Model of Rat. |
Kim, Wook Ro , Ahn, Sang Ho , Cho, Yun Woo , Cho, Hee Kyung , Kim, Han Seon , Kim, Su Jeong , Seo, Jeong Min |
1Department of Rehabilitation Medicine, College of Medicine, Yeungnam University, Korea. spineahn@yumail.ac.kr 2Institute of Medical Science, Yeungnam University, Korea. |
요추간 수핵 이식 모델에서 신경병증성 방사통의 장기 지속 양상 |
김욱로, 안상호, 조윤우, 조희경, 김한선, 김수정1, 서정민1 |
영남대학교 의과대학 재활의학교실, 1영남대학교 의료공학연구소 |
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Abstract |
Objective To observe the long-lasting changes of pain progression with time course in an autologous nucleus pulposus model of rat. Method The subjects were 25 Sprague-Dawley (Sprague- Dawley, 250 gm) male rats. They were randomly assigned into either the sham or experimental group. In the experimental group (n=15), autologous nucleus pulposus was harvested from the coccygeal intervertebral disc of the rat and this was grafted on the left L5 dorsal root ganglion. In the sham group (n=10), the left L4 and L5 nerve roots were exposed by laminectomy, but the nucleus pulposus was not grafted. All the rats were evaluated for mechanical allodynia and thermal hyperalgesia at 2 days before surgery, and on days 1, 5, 10, 20, 30, 40 and 50 after surgery. The morphological changes of the spinal nerves were assessed by toluidine blue staining on days 5 after surgery. Results In the ipsilateral hindpaw of the experimental group, there was a dramatic drop of the mechanical withdrawal threshold and the thermal withdrawal latency on day 1 after surgery, which was maintained at day 50 after surgery. In morphological study, pathological findings such as swelling of the myelin sheath, demyelination, swelling and degeneration of the axoplasm were observed in the spinal nerve at day 5 after surgery. Conclusion The long-lasting pattern of neuropathic radicular pain shown in a rat model of lumbar disc herniations is helpful to understand the natural history of neuropathic radicular pain due to ruptured nucleus pulposus. (J Korean Acad Rehab Med 2009; 33: 477-482) |
Key Words:
Autologous nucleus pulposus model, Mechanical allodynia, Thermal hyperalgesia, Neuropathic radicular pain |
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