Wiberg M, Ljungberg C, O'Byrne A, Brown R, Whitworth I, Liss A, Terenghi G
Department of Anatomy, Umeå University, Sweden.
Scand J Plast Reconstr Surg Hand Surg. 1999 Dec;33(4):387-92. doi: 10.1080/02844319950159082.
Nerve injuries induce neurochemical changes within primary sensory neurons, including expression of neuropeptides, and a loss of a substantial proportion of the neurons may possibly be caused by a lack of neurotrophic support. In the present study the role of nerve growth factor (NGF) in preventing these changes was investigated in monkeys by giving NGF peripherally through a fibronectin (Fn) conduit. A sensory nerve (superficial radial) was transected and a gap of 5 mm was bridged with either autologous sural nerve graft (SNG), Fn, or Fn impregnated with NGF (Fn-NGF). After four months the dorsal root ganglia, that received the cutaneous afferents of the nerve, were removed and analysed by quantitative immunohistochemistry using antibodies to calcitonin gene related polypeptide (CGRP) and substance P. The percentage of immunostained cells was taken as an indication of neuronal survival. The results showed that SNG and Fn-NGF reduced the loss of CGRP positive sensory neurons compared with Fn alone. For substance P-positive neurons the differences were small with only a tendency towards reduction of neuronal death after NGF had been given, suggesting that NGF might act preferentially on a subpopulation of CGRP immunoreactive sensory neurons that do not coexist with substance P.
神经损伤会在初级感觉神经元内引发神经化学变化，包括神经肽的表达，并且相当一部分神经元的丧失可能是由于缺乏神经营养支持所致。在本研究中，通过纤连蛋白（Fn）导管经外周给予神经生长因子（NGF），在猴子身上研究了NGF在预防这些变化中的作用。切断一条感觉神经（桡浅神经），用自体腓肠神经移植物（SNG）、Fn或浸渍有NGF的Fn（Fn-NGF）桥接5毫米的间隙。四个月后，取出接受该神经皮肤传入纤维的背根神经节，并用抗降钙素基因相关肽（CGRP）和P物质的抗体通过定量免疫组织化学进行分析。免疫染色细胞的百分比被用作神经元存活的指标。结果表明，与单独使用Fn相比，SNG和Fn-NGF减少了CGRP阳性感觉神经元的丧失。对于P物质阳性神经元，差异较小，仅在给予NGF后有神经元死亡减少的趋势，这表明NGF可能优先作用于不与P物质共存的CGRP免疫反应性感觉神经元亚群。
