Longo F M, Skaper S D, Manthorpe M, Williams L R, Lundborg G, Varon S
Exp Neurol. 1983 Sep;81(3):756-69. doi: 10.1016/0014-4886(83)90342-4.
The presence of neuronotrophic factors (NTFs) in noninjured sciatic nerve extract and the course of their accumulation from 3 h to 30 days after nerve transection was examined. Rat sciatic nerves were transected and their proximal and distal stumps sutured into the openings of cylindrical silicone chambers leaving a 10-mm interstump gap. Previous studies had shown that regeneration occurs in chambers containing both stumps but is absent in chambers lacking the distal stump. Chambers became completely filled with fluid 10 to 12 h after implantation. Fluid from chambers without nerve stumps (open-ended) implanted adjacent to nerve-containing chambers had markedly lower trophic activities than those containing one or both stumps. In fluid collected from chambers containing both proximal and distal nerve stumps, the highest titers of NTFs directed to sensory neurons were measured at 3 h posttransection whereas the highest titers of NTFs directed to sympathetic and spinal cord neurons were detected at 1 and 3 days, respectively. Chambers containing only the proximal or only the distal stumps showed similar temporal dynamics for sensory and sympathetic NTFs. Sensory and sympathetic neuronotrophic activity in extracts of proximal and distal stumps followed a similar temporal course to those in chamber fluid. Extracts of nonlesion nerve segments 5 mm from the transection site contained higher sensory and lower sympathetic trophic activity than extracts including the transection site. Spinal cord activity was undetectable in all extracts. Antiserum to nerve growth factor had no effect on fluid or extracts containing high sensory or sympathetic activities. These observations suggested that (i) some NTFs may be present in normal nerves and others may be synthesized or accumulated in response to nerve injury, (ii) sensory, sympathetic, and spinal cord NTFs are separate agents and immunochemically distinct from nerve growth factor, (iii) NTFs predominantly originate from nerve stumps rather than from surrounding fluid, and (iv) proximal and distal nerve stumps accumulate and release NTFs at similar rates.
研究了未损伤坐骨神经提取物中神经营养因子（NTFs）的存在情况以及神经横断后3小时至30天内其积累过程。将大鼠坐骨神经横断，其近端和远端残端缝合到圆柱形硅胶室的开口处，残端间留10毫米间隙。先前研究表明，在包含两个残端的室中会发生再生，但在没有远端残端的室中则不会。植入后10至12小时，室完全充满液体。与含神经的室相邻植入的无神经残端（开口端）室中的液体，其营养活性明显低于含有一个或两个残端的室中的液体。在从包含近端和远端神经残端的室中收集的液体中，针对感觉神经元的NTFs最高滴度在横断后3小时测得，而针对交感神经和脊髓神经元的NTFs最高滴度分别在1天和3天检测到。仅包含近端或仅包含远端残端的室，其感觉和交感NTFs呈现相似的时间动态。近端和远端残端提取物中的感觉和交感神经营养活性与室液体中的活性遵循相似的时间进程。离横断部位5毫米的未损伤神经节段提取物中的感觉营养活性较高，交感营养活性较低，而包含横断部位的提取物则相反。在所有提取物中均未检测到脊髓活性。针对神经生长因子的抗血清对含有高感觉或交感活性的液体或提取物没有影响。这些观察结果表明：（i）一些NTFs可能存在于正常神经中，其他NTFs可能是对神经损伤作出反应而合成或积累的；（ii）感觉、交感和脊髓NTFs是不同的因子，在免疫化学上与神经生长因子不同；（iii）NTFs主要起源于神经残端而非周围液体；（iv）近端和远端神经残端以相似的速率积累和释放NTFs。
