Li B, Wang Z, Zhu P
Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing.
Zhonghua Yi Xue Za Zhi. 1997 Jul;77(7):516-20.
To study the changes of (brain-derived neurotrophic factor) BDNF mRNA during embroyonic spinal cord repairing spinal cord injury of adult rats.
At day 1,3, 5, 7, 10, 15, and 30 after embryonic spinal cord being transplanted into acutely injured spinal cord of adult rats, changes of BDNF mRNA within donor tissue and host tissue were demonstrated qualitatively and quantitatively by in situ hybridization and dot hybridization.
Qualitatively, BDNF mRNA was mainly expressed within cytoplasm of motor neurons and a few gliocytes in normal spinal cord. After spinal cord injury, hybridizing products expanded to the mediate and small-sized neurons, also more gliocytes took part in hybridization response. Following transplantation, positively hybridizing neurons and gliocytes increased in number in host tissue, and embryonic spinal cord kept an expressing level similar to that before being transplanted. It was also revealed quantitatively that reacting intensity of the cells in the injured group was strikingly higher than that in the normal group. However, hybridization intensity in the transplanted group was even higher at many intervals than that in the injured group. Besides, the lasting period for hybridization reaction in the transplanted group was also different from that in the injured group. The most intensive reacting phase in the former presented at day 10 and 15, and in the latter at day 7 after operation.
We suggest that transplanted embryonic spinal cord can, besides provision neurol trophines for itself and host spinal cord, evoke synthetic mechanisms of host spinal cord once holding during its embryonic development so as to enhance expression of the neurotrophin. In this way, the host spinal cord may provide neurotrophin for its regeneration and provide an trophic environment for the grafts to develop and differentiate.
研究胚胎脊髓移植修复成年大鼠脊髓损伤过程中脑源性神经营养因子（BDNF）mRNA的变化。
将胚胎脊髓移植到成年大鼠急性损伤的脊髓后第1、3、5、7、10、15和30天，采用原位杂交和斑点杂交技术对供体组织和宿主组织内BDNF mRNA的变化进行定性和定量分析。
定性分析显示，正常脊髓中BDNF mRNA主要表达于运动神经元的细胞质及少数胶质细胞内。脊髓损伤后，杂交产物扩展至中、小型神经元，且更多胶质细胞参与杂交反应。移植后，宿主组织中阳性杂交的神经元和胶质细胞数量增加，胚胎脊髓保持与移植前相似的表达水平。定量分析还显示，损伤组细胞的反应强度明显高于正常组。然而，移植组在多个时间点的杂交强度甚至高于损伤组。此外，移植组杂交反应的持续时间也与损伤组不同。前者最强烈的反应阶段出现在术后第10和15天，后者出现在术后第7天。
我们认为，移植的胚胎脊髓除了为自身和宿主脊髓提供神经营养因子外，还能激活宿主脊髓在胚胎发育期间曾经拥有的合成机制，从而增强神经营养因子的表达。通过这种方式，宿主脊髓可为自身再生提供神经营养因子，并为移植物的生长和分化提供营养环境。
