Objective:To study the protection of acanthopanax senticosus injection to sciatic nerve injury in rats. Methods:SD rats were randomly divided into normal group, model group, treatment group 1 (20mg/kg. d), treatment group 2 (40mg/kg. d). The left sciatic nerves of rats were performed with chucking method to estab-lish sciatic nerve injury model, injection continued for 6 weeks from then on. Observe the temperature of left foot skin, the rat sciatic nerve function index ( SFI) , the sciatic nerve conduction velocity ( SNCV) and the morpholog-ical changes of nerve tissue, immunohistochemical staining and Western Blot were used to observe the expression of nerve growth factor. Results:Acanthopanax senticosus injection (20mg/kg. d, 0mg/kg. d) can raise the rat skin temperature, promote the function recovery of sciatic nerve, accelerate the conduction velocity of sciatic nerve, make the morphological changes of nerve tissue better, increased the expression of nerve growth factor, and there was a significant difference between this two treatment groups. Conclusions:Protective effect of acanthopanax sen-ticosus injection on peripheral nerve injury in rats may be associated with promoting the expression of nerve growth factor.

The purpose of this work was to investigate whether, by intranasal administration, the nerve growth factor bypasses the blood-brain barrier and turns over the spinal cord neurons and if such therapeutic approach could be of value in the treatment of spinal cord injury. Adult Sprague-Dawley rats with intact and injured spinal cord received daily intranasal nerve growth factor administration in both nostrils for 1 day or for 3 consecutive weeks. We found an in-creased content of nerve growth factor and enhanced expression of nerve growth factor receptor in the spinal cord 24 hours after a single intranasal administration of nerve growth factor in healthy rats, while daily treatment for 3 weeks in a model of spinal cord injury improved the deifcits in locomotor behaviour and increased spinal content of both nerve growth factor and nerve growth factor receptors. These outcomes suggest that the intranasal nerve growth factor bypasses blood-brain barrier and affects spinal cord neurons in spinal cord injury. They also suggest exploiting the possible therapeutic role of intranasally delivered nerve growth factor for the neuroprotection of damaged spinal nerve cells.

Rapamycin, similar to FK506, can promote neural regeneration in vitro. We assumed that the mechanisms of action of rapamycin and FK506 in promoting peripheral nerve regeneration were similar. This study compared the effects of different concentrations of rapamycin and FK506 on Sc hwann cells and investigated effects and mechanisms of rapamycin on improving peripheral nerve regeneration. Results demonstrated that the lowest rapamycin concentration (1.53 nmol/L) more signiifcantly promoted Schwann cell migration than the highest FK506 concentration (100μmol/L). Rapamycin promoted the secretion of nerve growth factors and upregulated growth-associated protein 43 expression in Schwann cells, but did not signiifcantly affect Schwann cell proliferation. Therefore, rapamycin has potential application in peripheral nerve regeneration therapy.

Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as wel as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. Electro-physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation il ustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits com-bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits.

Under normal conditions, the sympathetic neurotransmitter noradrenaline inhibits the pro-duction and release of pro-inlfammatory cytokines. However, after peripheral nerve and tissue injury, pro-inflammatory cytokines appear to induce the expression of the alpha1A-adreno-ceptor subtype on immune cells and perhaps also on other cells in the injured tissue. In turn, noradrenaline may act on up-regulated alpha1-adrenoceptors to increase the production of the pro-inflammatory cytokine interleukin-6. In addition, the release of inflammatory mediators and nerve growth factor from keratinocytes and other cells may augment the expression of al-pha1-adrenoceptors on peripheral nerve ifbers. Consequently, nociceptive afferents acquire an abnormal excitability to adrenergic agents, and inlfammatory processes build. These mechanisms could contribute to the development of sympathetically maintained pain in conditions such as post-herpetic neuralgia, cutaneous neuromas, amputation stump pain and complex regional pain syndrome.

Our previous findings confirmed that the nerve growth factor-containing fibrin glue membrane pro-vides a good microenvironment for peripheral nerve regeneration;however, the precise mechanism remains unclear. p75 neurotrophin receptor (p75NTR) plays an important role in the regulation of pe-ripheral nerve regeneration. We hypothesized that a nerve growth factor-containing fibrin glue membrane can promote neural regeneration by up-regulating p75NTR expression. In this study, we used a silicon nerve conduit to bridge a 15 mm-long sciatic nerve defect and injected a mixture of nerve growth factor and fibrin glue at the anastomotic site of the nerve conduit and the sciatic nerve. Through RT-PCR and western blot analysis, nerve growth factor-containing fibrin glue membrane significantly increased p75NTR mRNA and protein expression in the Schwann cells at the anasto-motic site, in particular at 8 weeks after injection of the nerve growth factor/fibrin glue mixture. These results indicate that nerve growth factor-containing fibrin glue membrane can promote pe-ripheral nerve regeneration by up-regulating p75NTR expression in Schwann cells.

NGF促进神经细胞生长发育的信号通路及与哮喘发病的关系

神经生长因子(NGF)作为第一个被发现的神经营养因子,具有促进神经细胞存活和生长发育的作用.NGF结合酪氨酸受体TrkA,引起胞内四条信号通路:Ras/Raf/Erk蛋白激酶通路,磷脂酰肌醇-3激酶(PI3-K)/Akt激酶通路,磷脂酶c(PLC-γ)通路以及SNT.NGF的另一个受体P75神经营养因子受体(P75NTR)的信号通路仍不是十分清楚,但可与TrkA协同作用,也可单独作用促进神经细胞的存活或凋亡.另外,NGF介导下TrkA的信号通路与哮喘的发病之间有着密切的联系.本文主要就NGF与TrkA和P75NTR蛋白结合后,胞内传导系统及尚待研究解决的问题进行综述.

神经生长因子和碱性成纤维细胞生长因子联用治疗坐骨神经损伤实验研究

AIM:To explore the co- effect of nerve growth factor (NGF) and basic fibroblast growth factor (bFGF) on the sciatic nerve after injury. METHODS: 96 rats were divided into normal saline group, NGF group, bFGF group and NGF+ bFGF group. Sciatic nerve function index (SFI), nerve conduction velocity, regeneration axon counting were detected in the 3 rd, 6 th, 9 th, 12 th week postinjury. RESULTS:The end of SFI, nerve conduction velocity, regeneration axon counting in NGF+ bFGF group were higher than those in the other groups. CONCLUSION:The co- effect of NGF and bFGF on sciatic nerve is better than the effect of NGF or bFGF alone.

外源性神经节苷脂对脑损伤的保护作用

AIM: To investigate protection function of ectogenesis ganglioside (GM1)to brain injury of epilepsy rats. METHODS: Inducing rat epilepsy model with sulfo-semicarbazide(7.5mg/kg), dynamically observe nerve growth factor (NGF) expression of epilepsy group and GM1 intervention group in Hippocampus and cerebral cortex nerve cell 24 h, 48 h, 72 h and 7 d after epileptic attack and control group after 72 h with immunohistochemistry method. At same time we observed change of nerve cell shape and structure with electron microscope techniques. RESULTS: Electron microscope showed nerve cell injury of epilepsy rats but injury relieved after GM1 intervention. CONCLUSION: GM1 play some protective function to brain injury of epilepsy rats through induced NGF expression increase.

神经生长因子及其受体TrkA、p75NTR在隆凸性皮肤纤维肉瘤和皮肤纤维瘤中的表达

目的 探讨神经生长因子(NGF)及其受体酪氨酸激酶A(TrkA)、p75神经营养因子受体(p75NTR)在隆凸性皮肤纤维肉瘤和皮肤纤维瘤中的表达. 方法 应用免疫组化ABC法检测隆凸性皮肤纤维肉瘤石蜡标本17例、皮肤纤维瘤石蜡标本15例中NGF及其受体TrkA、p75NTR表达.结果 NGF及TrkA在隆凸性皮肤纤维肉瘤及皮肤纤维瘤中均呈高表达,两者之间差异无统计学意义(x2=0.11,0.02,P值均＞0.05)；而p75NTR在隆凸性皮肤纤维肉瘤中的表达显著高于皮肤纤维瘤(x2=32,P＜0.01),且NGF与p75NTR在隆凸性皮肤纤维肉瘤表达呈正相关(R2=0.623,P＜ 0.01).结论 NGF可能通过其高亲和受体TrkA及低亲和受体p75NTR在隆凸性皮肤纤维肉瘤的发病中起一定作用.

鼠神经生长因子联合神经松解术治疗自发性腓总神经卡压症的疗效观察

自发性腓总神经卡压症是临床比较常见的一种周围神经卡压症［1］。腓总神经由于解剖位置表浅，易受到压迫、牵拉以及局部解剖结构变异等多因素影响而产生足背伸功能及感觉功能障碍，患者常因跨域步态而严重影响日常生活及工作。本科应用神经松解术联合术中及术后辅助使用鼠神经生长因子（mouse Nerve Growth Factor， mNGF）治疗自发性腓总神经卡压症取得良好效果。报告如下。

鼠神经生长因子治疗26例面神经损伤的疗效观察

本院自2000年2月至2005年2月,共收治因头部外伤后颅底骨折引起的面神经损伤共48例,其中应用鼠神经生长因子治疗26例,疗效满意.现报告如下.

AIM: The aim of this study was to explore the expression of nerve growth factor(NGF) in spinal dorsal horn following crushed spinal cord injury. METHODS: The adult Srague-Dawley rat model of crushed spinal cord injury was established by the method in our laboratory, and intact spinal cord was used as control. The rats were sacrificed respectively after 24 hours, 7 days, and 21 days of operation, and the L3 spinal segments were removed out and fixed in 4% polyformaldehyde. The segments were sectioned into sections of 20 μm in thickness. The sections were stained with anti-NGF antibody by ABC method of immunohistochemistry technique. The immunoreactive intensity of NGF and the number of positive neurons as well as glial cells in dorsal horn were observed and counted under light microscope. RESULTS: The number of positive cells and immunoreactive intensity of NGF increased gradually in the dorsal horn at 24 hours, 7 days and 21 days following crushed spinal cord injury compared with control group (P＜0.01). CONCLUSION: These results indicated that NGF plays an important role in the postoperative reaction during the early period of the crushed spinal cord injury.