Edbladh M, Edström A, Persson L
Department of Zoophysiology, University of Lund, Sweden.
Exp Neurol. 1990 Jan;107(1):63-8. doi: 10.1016/0014-4886(90)90063-x.
The current study examined both in vivo and in vitro the effects of alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), on regeneration of sensory axons from a local crush of the adult frog sciatic nerve. If daily injections of DFMO started at the same time as crushing and continued throughout the regeneration period (7 days) the outgrowth in vivo of new sensory axons was reduced by about 30%. If DFMO injections started 2 days after crushing, the outgrowth distance did not differ from control values. The sensory axons of a cultured frog sciatic nerve with the attached spinal ganglia start to regenerate from a local crush applied 7 days after the start of the incubation. Five days after crushing the outgrowth distance was 4.5 mm. At the end of the culturing period (7 + 5 days) both the putrescine and spermidine concentrations in the ganglia had increased about 2.5 times, whereas the spermine concentration remained constant. The presence of 10 mM DFMO throughout the culturing period, 7 + 5 days, almost depleted putrescine and prevented the spermidine increase in the ganglia without affecting the regeneration distance. In the nerve putrescine was only reduced by 55% and the other polyamines were unaffected by DFMO. The results show that DFMO influences the early onset of regeneration in vivo. The in vitro results indicate that this is not due to a close mechanistic relationship between the perikaryonal ODC/polyamine system and nerve regeneration. The question of whether polyamines are of local importance for regeneration of the frog sciatic nerve cannot be answered by the present results.
本研究在体内和体外检测了鸟氨酸脱羧酶（ODC）的不可逆抑制剂α-二氟甲基鸟氨酸（DFMO）对成年青蛙坐骨神经局部挤压后感觉轴突再生的影响。如果在挤压的同时开始每日注射DFMO，并在整个再生期（7天）持续注射，新感觉轴突在体内的生长会减少约30%。如果在挤压后2天开始注射DFMO，其生长距离与对照值没有差异。带有相连脊髓神经节的培养青蛙坐骨神经的感觉轴突，在培养开始7天后施加局部挤压后开始再生。挤压5天后，生长距离为4.5毫米。在培养期结束时（7 + 5天），神经节中的腐胺和亚精胺浓度均增加了约2.5倍，而精胺浓度保持不变。在整个7 + 5天的培养期内加入10 mM DFMO，几乎耗尽了腐胺并阻止了神经节中亚精胺的增加，但不影响再生距离。在神经中，腐胺仅减少了55%，其他多胺不受DFMO影响。结果表明，DFMO影响体内再生的早期开始。体外实验结果表明，这并非由于核周ODC/多胺系统与神经再生之间存在密切的机制关系。本研究结果无法回答多胺对青蛙坐骨神经再生是否具有局部重要性这一问题。
