Alginate enhances elongation of early regenerating axons in spinal cord of young rats
Alginate enhances elongation of early regenerating axons in spinal cord of young rats
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DOI：
10.1089/107632704323061852
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发表时间：
2004-03-01
影响因子：
--
通讯作者：
Ide, C
中科院分区：
文献类型：
--
作者：
Kataoka, K;Suzuki, Y;Ide, C
冷冻干燥的海藻酸盐海绵与共价键交联已被证明可以增强周围神经和脊髓中的神经再生。本研究观察了幼年大鼠脊髓全横断后早期再生轴突的生长和星形胶质细胞的反应。切除两个节段（Th 7 -8），并将藻酸盐植入病变中。作为对照，胶原凝胶植入代替藻酸盐或病变留下而不植入。术后2周和4周，检查神经生长和星形胶质细胞反应。许多再生轴突，其中一些伴随着星形胶质细胞的过程，被发现从残端延伸到藻酸盐植入病变。在所有未植入的动物中，在两个界面处均形成大的囊腔，没有明确的轴突长入病变。在植入胶原蛋白的动物中，在一些大鼠中发现了空腔形成，并且在残端处一旦形成再生轴突就不会进一步延伸到病变中。星形胶质细胞的进程延伸到藻酸盐植入病变没有基底层，而在对照实验中发现的基底层所覆盖。这些发现表明，藻酸盐有助于减少由结缔组织和反应性星形胶质细胞突起组成的屏障，并作为再生轴突生长和星形胶质细胞突起伸长的支架。
Freeze-dried alginate sponge cross-linked with covalent bonds has been demonstrated to enhance nerve regeneration in peripheral nerves and spinal cords. The present study examined, at early stages after surgery, the outgrowth of regenerating axons and reactions of astrocytes at the stump of transected spinal cord in young rats. Two segments (Th7-8) were resected, and alginate was implanted in the lesion. As controls, collagen gel was implanted in place of alginate or the lesion was left without implantation. Two and 4 weeks after surgery, nerve outgrowth and astrocyte reactions were examined. Many regenerating axons, some of which were accompanied by astrocytic processes, were found to extend from the stump into the alginate-implanted lesion. In the all nonimplanted animals, large cystic cavities were formed at both interfaces with no definite axonal outgrowth into the lesion. In collagen-implanted animals, cavity formation was found in some rats, and regenerating axons once formed at the stumps did not extend further into the lesion. Astrocytic processes extending into alginate-implanted lesion had no basal laminae, whereas those found in control experiments were covered by basal laminae. These findings suggest that alginate contributed to reducing the barrier composed of connective tissues and reactive astrocytic processes, and served as a scaffold for the outgrowth of regenerating axons and elongation of astrocytic processes.