Effects of nerve growth factor on crushed sciatic nerve regeneration in rats

The effects of nerve growth factor (NGF) on crushed sciatic nerve regeneration were studied in 30 rats, with 60 bilateral nerves. The nerves were crushed at a site 6 mm distal to the sciatic notch by the standard technique and 3 mm wide crush injuries were created. Then 2.1 μl of normal saline in the control groups and an equal volume of NGF solution (containing 1 μg of NGF) in the NGF-treated groups was injected into the crush sites and followed for 12, 28, and 56 days, respectively. At the end of the observation, electrophysiological evaluation was carried out; then samples 10 mm distal to the crush site were removed and prepared for histological and morphometric studies. Evoked muscle action potential (MAP) was recorded in 50% of the NGF-treated group at 12 days but not in the control group; the difference was statistically significant (P<0.05). The motor nerve conduction velocity (MNCV) was increased in NGF-treated groups compared with control groups at 28 and 56 days (P<0.05). Morphometrically, significantly more regenerated myelinated fibers (RMFs) were seen at 12 days, and larger diameter RMFs were found at 12, 28, and 56 days in NGF-treated groups than in control groups. These results indicate that topically applied NGF stimulates nerve regeneration and promotes function recovery in crushed rat sciatic nerves. © 1995 Wiley-Liss, Inc.     

联合使用ATP和NGF对周围神经再生作用的实验研究

目的 研究三磷酸腺苷(adenosine tri-phosphate，ATP)和神经生长因子(nerve growth factor，NGF)联合使用时对受损周围神经再生的作用并比较两者作用的强弱。方法 将64只SD大鼠左侧坐骨神经切断后直接作端端缝合，缝合段置于硅胶管室内。根据室内注入药物的不同，分为生理盐水(NS)、ATP、NGF、和ATP加NGF4组，每组16只大鼠。术后4周和8周(每组均为8只)取标本，作形态学，肌湿重，运动神经传导速度(MNCV)、复合运动动作电位(CMAP)波幅，及组织学的检测。结果 ATP加NGF组的神经纤维数目、大小、髓鞘厚度和MNCV、CMAP及肌湿重均优于其它3个组。NGF组的各项指标比ATP组好。结论联合使用ATP和NGF时受损周围神经的再生作用明显增强。NGF的作用强于ATP。     

促红细胞生成素促进大鼠坐骨神经再生作用的实验研究

目的 探讨促红细胞生成素(Erythoropoietin,EPO)对大鼠坐骨神经损伤修复后神经再生的影响,为周围神经损伤的临床治疗提供实验依据.方法 雄性SD大鼠40只,随机分为两组,即EPO组和神经生长因子(NGF)组,用硅胶管桥接10 mm的坐骨神经缺损,EPO组和NGF组分别注射EPO和NGF.术后4周和8周时每组分别提取10只大鼠,以坐骨神经功能指数(SFI)、运动神经传导速度(MNCV)、形态学观察和蛋白基因产物9.5(PGP 9.5)免疫组织化学染色,评估EPO对大鼠坐骨神经再生的影响.结果 术后4周SFI,EPO组为[(-78.85±3.87),x-±s,下同],NGF组为(-79.98±4.58),差异无统计学意义(P>0.05);术后8周SFI,EPO组为(-60.26±2.91),NGF组为(-64.65±4.11),差异有统计学意义(P<0.05).术后4周和8周时,EPO组MNCV、有髓神经纤维数目以及PGP9.5免疫阳性神经纤维的平均光密度和积分光密度均优于NGF组,差异有统计学意义(P<0.05).结论 EPO 能促进大鼠坐骨神经损伤后的修复与再生.     

局部应用复方红芪对周围神经损伤修复后影响的实验研究

目的　比较大鼠坐骨神经局部应用复方红芪提取液和神经生长因子 (NGF)的效果 ,并观察复方红芪提取液对周围神经再生的促进作用。方法　SD雄性大鼠 3 5只 ,各鼠编号后分成 4组。建立双侧坐骨神经损伤模型 ,于神经损伤段周围肌肉间隙内注射药物。红芪组每侧注射复方红芪提取液 0 .4ml;NGF组每侧注射 10 0U ;对照组每侧注射生理盐水 0 .4ml ;正常对照组不作处理。术前、术后 4周测定坐骨神经功能指数 (SFI)及坐骨神经运动传导速度 (MNCV)。结果　SFI :红芪组优于NGF组和对照组(P =0 .0 11、0 .0 0 4) ,和正常对照组比两者差异无显著性意义 (P =0 .5 2 )。MNCV :红芪组与NGF组两者差异无显著性意义 (P =0 .5 2 ) ,但均优于对照组而低于正常对照组 (P均 <0 .0 1)。结论　复方红芪提取液可有效地促进大鼠周围神经损伤后的再生 ,且运动功能恢复指标优于NGF。     

睫状神经营养因子神经生长因子对周围神经再生的作用

目的：研究睫状神经营养因子（ｃｉｌｉａｒｙｎｅｕｒｏｔｒｏｐｈｉｃｆａｃｔｏｒ，ＣＮＴＦ）和神经生长因子（ｎｅｒｖｅｇｒｏｗｔｈｆａｃｔｏｒ，ＮＧＦ）对周围神经再生的作用。方法：硅管套接大鼠坐骨神经，将ＣＮＴＦ、ＮＧＦ、生理盐水（ｎｏｒｍａｌｓａｌｉｎｅｓｏｌｕｔｉｏｎ，ＮＳ）分别加入硅管中，并于术后每日皮下注射一定剂量。术后４周，应用ＨＲＰ逆行追踪技术显示再生轴突通过修复部位的胞体。结果：与ＮＳ组、ＮＧＦ组相比，ＣＮＴＦ组脊髓标记胞体显著增加，其它组间比较，差异不显著。结论：外源性ＣＮＴＦ能明显促进周围神经运动轴突再生，但促进感觉轴突再生的作用不明显。外源性ＮＧＦ促进周围神经运动和感觉轴突的再生均不明显     

Enhanced rat sciatic nerve regeneration through silicon tubes filled with pyrroloquinoline quinone

Pyrroloquinoline quinone (PQQ) is an antioxidant that also stimulates nerve growth factor (NGF) synthesis and secretion. In an earlier pilot study in our laboratory, Schwann cell growth was accelerated, and NGF mRNA expression and NGF secretion were promoted. The present study was designed to explore the possible nerve-inducing effect of PQQ on a nerve tube model over a 1-cm segmental deficit. An 8-mm sciatic nerve deficit was created in a rat model and bridged by a 1-cm silicone tube. Then,10 mul of 0.03 mmol/l PQQ were perfused into the silicone chamber in the PQQ group. The same volume of normal saline was delivered in the control group. Each animal underwent functional observation (SFI) at 2-week intervals and electrophysiological studies at 4-week intervals for 12 weeks. Histological and morphometrical analyses were performed at the end of the experiment, 12 weeks after tube implantation. Using a digital image-analysis system, thickness of the myelin sheath was measured, and total numbers of regenerated axons were counted. There was a significant difference in SFI, electrophysiological index (motor-nerve conduct velocity and amplitude of activity potential), and morphometrical results (regenerated axon number and thickness of myelin sheath) in nerve regeneration between the PQQ group and controls (P < 0.05). More mature, high-density, newly regenerated nerve was observed in the PQQ group. We conclude that PQQ is a potent enhancer for the regeneration of peripheral nerves.     

靶肌肉注射甲状腺素促进周围神经再生的实验研究

目的研究在靶肌肉注射甲状腺素(T3)对周围神经再生的作用。方法将60只大鼠随机分为实验组和对照组,每组30只。硅胶管桥接大鼠坐骨神经,实验组于术后每周2次将甲状腺素注射于伤侧胫前肌和腓肠肌上,术后1个月和3个月,应用运动神经传导速度(MNCV)、光镜、透射电镜等方法分别从功能和形态方面测定各项指标;对照组注射等量的生理盐水。结果实验组再生神经在功能和形态方面均优于对照组。结论靶肌肉注射甲状腺素能有效促进周围神经再生。     

Eeffect of nerve growth factor on changes of myelin basic protein and functional repair of peripheral nerve following sciatic nerve injury in rats

OBJECTIVE: To investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury. METHODS: The sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD-4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP. RESULTS: The latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P<0.05). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP-positive cells in the Group A than in the Group B in one and four weeks respectively. CONCLUSIONS: NGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.     

Local administration of neurotrophic growth factor in subcutaneous silicon chambers enhances the regeneration of the sensory component of the rat sciatic nerve.

An experimental model for local administration of neurotrophic growth factor (NGF) in peripheral nerve lesions is tested. The model consists of a subcutaneous reservoir connected to the sciatic nerve neurorrhaphy. The right sciatic nerves were exposed, severed, and repaired at a level 1.5 cm proximal to their trifurcation. Then, a dome-shaped silicone reservoir connected to the proximal end of a silicone tube was placed subcutaneously in the dorsum of the experimental animal. The distal end of the connecting tube was located in the nerve neurorrhaphy. Two experimental groups were made: Group A (n = 90) received daily doses of a solution containing NGF-7S during the first 4 weeks after surgery and a single weekly dose thereafter. Within this group, three subgroups of 30 rats each were made: A-4 sacrificed 4 weeks after surgery, A-8 sacrificed after 8 weeks, and A-12 after 12 weeks. Group B (n = 90) received the same vehicle solution without NGF under the same schedule and volume as in Group A. Three subgroups were also made as in Group A depending on the survival period. In order to locate the neurons in the dorsal root ganglia, the retrograde tracer horseradish peroxidase was administered at the proximal stump of the sciatic nerve (tibialis branch), which was severed 1 cm distal to the sciatic trifurcation. In respect of the nonoperated side, the percentage between the number of dorsal root ganglia neurons in the NGF-treated group was significantly higher than in the control group (P < 0.001). These results demonstrate that percutaneous administration of multiple doses of NGF in this model enhances sensory nerve regeneration after sciatic lesions evaluated by horseradish peroxidase labeling of dorsal root ganglia neurons.     

神经生长因子对运动终板变性与再生的研究

目的：探讨运动终板变性与再生时，神经生长因子（ＮＧＦ）对终板组织化学及超微结构变化的影响。方法：３０只Ｗｉｓｔａｒ大白鼠，切断股骨中段的坐骨神经，硅胶管桥接，两神经断端相距６ｍｍ。右侧再生室内注入ＮＧＦ，左侧注入生理盐水为对照侧。结果：终板乙酰胆碱酯酶染色，实验侧比对照侧着色深，末梢神经纤维再生丰富。术后１个月ＮＳ侧，终板区可见到雪旺氏细胞吞噬破碎的终板组织，出现典型的终板变性特征，而ＮＧＦ侧术后１个月突触裂隙内未发现雪旺氏细胞侵入。术后３个月ＮＧＦ侧再生运动终板结构接近正常，而ＮＳ侧终板结构不成熟。结论：当周围神经损伤后，损伤局部应用ＮＧＦ可减少运动终板变性的程度，促进了运动终板再生     

复方红芪减方对周围神经再生影响的实验研究

目的　研究复方红芪提取液进行减方后对周围神经再生的作用。方法　建立钳夹损伤大鼠双侧坐骨神经的动物模型。按术后每日灌服药物的不同将 40只SD雄性大鼠随机均分为 4组。对照组 :灌服生理盐水 ;复方红芪组 :灌服复方红芪提取液 2ml ;减方组 :灌服复方红芪减方后提取液 2ml;补阳还五汤组 :灌服补阳还五汤 2ml。术后 2周及 4周 ,观察坐骨神经功能指数、运动神经传导速度及单位视野有髓神经纤维计数。结果　坐骨神经功能指数 :红芪组和减方组与对照组、红芪组与减方组的差异均有显著意义 (P >0 .0 5 ) ,且减方组优于红芪组 (P >0 .0 5 )。有髓神经纤维计数 :复方红芪组优于对照组 (P<0 0 1) ,减方组明显优于对照组 (P <0 .0 1) ,而红芪组与减方组间无显著差异。运动神经传导速度 :红芪组、减方组、补阳还五汤组与对照组相比 ,均优于对照组 (P <0 .0 5 ) ,但前 3组间无明显差异。结论　复方红芪减方提取液早期可以促进周围神经再生 ,药效更为专一 ,且优于传统方剂补阳还五汤。     

银杏叶提取物对坐骨神经再生的影响

目的：研究银杏叶提取物局部应用对坐骨神经再生的影响。方法：选Wistar大鼠32只，随机分为银杏叶提取物组和对照组。在双目放大镜下切断两组大鼠右侧坐骨神经，于神经损伤处和周围肌肉间隙内注射药物后立即行缝合术。2周后进行坐骨神经功能指数、电生理学和组织形态学观测评定。结果：银杏叶提取物组各项指标均优于对照组，其坐骨神经功能指数的恢复、神经纤维的生长速度及数量明显优于对照组。结论：银杏叶提取物局部应用可有效促进大鼠坐骨神经损伤的早期再生，加快神经再生速度与神经功能恢复。     

再生小室内间断给予蛋白激酶C激动剂对周围神经表达NGF及损伤修复的影响

目的探讨大鼠坐骨神经再生小室内间断给予蛋白激酶C激动剂-佛波醇酯(phorbol-12-myristate-13-acetate,PMA)后,坐骨神经蛋白激酶C(protein kinase C, PKC)mRNA、神经生长因子(nerve growth factor, NGF)mRNA表达变化规律及轴突数目变化. 方法 SD大鼠42只行双侧坐骨神经中段切断约5 mm,"T"形硅胶管套接,随机分为6组,分别为损伤1、3天,1、2、3和4周组.右侧间断给予1×10-9mol/L PMA(PMA侧);左侧注射等量生理盐水(对照侧).采用组织切片核酸原位杂交(in situ hybridization,ISH)技术检测各组术后各不同点PKC mRNA和NGF mRNA在坐骨神经表达的动态变化及轴突数目变化. 结果对照侧大鼠坐骨神经PKC mRNA在损伤后表达上调,第2周达高峰后下降;NGF mRNA在损伤后表达上调,第3周达高峰值后下降.PMA侧PKC mRNA于第2、3和4周表达较对照侧明显增高,差异有统计学意义(P＜0.01或P＜0.05);NGF mRNA第2、3和4周表达也较对照侧明显增强,差异有统计学意义(P＜0.01).轴突数目在2、3和4周时多,差异有统计学意义(P＜0.01). 结论 PKC介导了周围神经损伤修复中的NGF mRNA表达及神经再生,而且PMA能够促进NGF mRNA表达及促进轴突生长.     

Regeneration of the motor component of the rat sciatic nerve with local administration of neurotrophic growth factor in silicone chambers

The experimental model reported consists of a subcutaneous reservoir connected to a rat sciatic nerve anastomosis. The right sciatic nerve was exposed, served, and repaired at a level 1.5 cm proximal to its trifurcation. Then, a dome-shaped silicone reservoir, connected to the proximal end of a silicone tube, was placed subcutaneously in the dorsum of the experimental animal. The distal end of the connecting tube was located at the nerve anastomosis. There were two experimental groups: Group A animals (n = 90) received daily doses of a solution containing nerve growth factor (NGF)-7S during the first 4 weeks after surgery and a single weekly dose thereafter. Within this group, there were three subgroups of 30 rats each: A-4 sacrificed at 4 weeks after surgery: A-8 sacrificed at 8 weeks; and A-12 at 12 weeks. Group B animals (n = 90) received the same vehicle solution without NGF at the same schedule and volumes as in Group A. There were also three subgroups as in Group A, depending on the survival period: B-4 (n = 30); B-8 (n = 30); and B-12 (n = 30). In order to localize the motoneurons in the spinal cord, the retrograde tracer, horseradish peroxidase (HRP), was administered at the proximal stump of the sciatic nerve (tibialis branch) that was severed 1 cm distal to the sciatic trifurcation (1.5 cm distal to the nerve anastomosis). The number of spinal neurons in the NGF-treated group was statistically significantly higher than in the control group (p < 0.001). These results demonstrate that percutaneous administration of multiple doses of neurotrophic growth factor in this model enhances motor nerve regeneration after sciatic lesions, evaluated by HRP-labeling of spinal motoneurons.     

Effects of topically administered nerve growth factor on axonal regeneration in peripheral nerve autografts implanted in the spinal cord of rats

The effect of exogenous nerve growth factor (NGF) on axonal regeneration into autologous peripheral nerve (PN) grafts implanted to the spinal cord (SC) of rats was assessed by retrograde labeling of the parent soma of the regenerating axons with horseradish peroxidase. NGF was delivered at the graft site over periods of 15 and 30 days by using indwelling osmotic minipumps. In control rats, the minipumps were filled with saline. At 15 days after grafting in the NGF-treated rats, the mean number of SC as well as dorsal root ganglion (DRG) neurons that regenerated their axons into the peripheral nerve grafts was increased 55.3 and 26.4 times, respectively, as compared to the control group values. At 30 days, SC and DRG neurons in the NGF-treated group were 10.9 and 3.1 times greater than in the control group. In the NGF-treated group, the regenerating SC neurons were located within a range of 7 to 13 mm from the graft site as compared to 1 to 7 mm in the control group. Finally, the analysis of the soma diameters of the regenerating neurons showed that NGF enhanced and maintained with time the regenerative response from small-sized DRG neurons. Therefore, NGF is thought to promote directly the regenerative potential of SC as well as DRG neurons and to exert an indirect glial cell-mediated effect at the SC-graft interface.     

Effects of basic fibroblast growth factor on experimental diabetic neuropathy in rats

Basic fibroblast growth factor (bFGF) stimulates angiogenesis and induces neural cell regeneration. We investigated the effects of bFGF on diabetic neuropathy in streptozotocin-induced diabetic rats. Diabetic rats were treated with human recombinant bFGF as follows: 1) intravenous administration, 2) intramuscular injection into thigh and soleus muscles with cross-linked gelatin hydrogel (CGH), and 3) intramuscular injection with saline. Ten or 30 days later, the motor nerve conduction velocity (MNCV) of the sciatic-tibial and caudal nerves, sensitivity to mechanical stimuli, sciatic nerve blood flow (SNBF), and retinal blood flow (RBF) were measured. Delayed MNCV in the sciatic-tibial and caudal nerves, hypoalgesia, and reduced SNBF in diabetic rats were all ameliorated by intravenous administration of bFGF after 10, but not 30, days. Intramuscular injection of bFGF with CGH also improved sciatic-tibial MNCV, hypoalgesia, and SNBF after 10 and 30 days, but caudal MNCV was not improved. However, intramuscular injection of bFGF with saline had no significant effects. bFGF did not significantly alter RBF in either normal or diabetic rats. These observations suggest that bFGF could have therapeutic value for diabetic neuropathy and that CGH could play important roles as a carrier of bFGF.     

丙戊酸钠充填导管促进大鼠外周神经再生的实验研究

目的 观察丙戊酸钠(VPA)充填导管对缺损外周神经再生的促进作用.方法 通过建立大鼠坐骨神经缺损模型.用硅胶管(1 cm)进行缺损神经段(0.8 cm)的桥接,局部应用8%VPA注射液10ul,观察VPA对神经再生和运动神经功能恢复的影响.30只大鼠随机分成2组,实验组在硅胶管局部注射VPA注射液;对照组在硅胶管局部注入生理盐水. 结果 术后每只大鼠每2周进行坐骨神经功能指数(SFI)检测,每4周做电生理检查,最后术后12周处死所有大鼠,对坐骨神经进行组织形态学分析.用数字图像分析软件检测有髓神经纤维髓鞘厚度.并对再生神经纤维轴突计数.通过统计软件分析发现SFI,电生理检查,神经组织性形态上两组差异均有统计学意义(P＜0.05). 结论 局部使用VPA于神经缺损的大鼠,可以促进损伤神经的轴突再生和运动功能恢复.因此VPA有望在临床上应用于外周神经损伤病例的治疗.     

Nerve growth factor accelerates wound healing in diabetic mice.

Patients with diabetic neuropathy have reduced numbers of cutaneous nerves, which may contribute to an increased incidence of nonhealing wounds. Nerve growth factor (NGF) has been reported to augment wound closure. We hypothesized that topical 2.5S NGF, a biologically active subunit of the NGF polymer, would accelerate wound repair, augment nerve regeneration, and increase inflammation in excisional wounds in diabetic mice. A full-thickness 6-mm punch biopsy wound was created on the dorsum of C57BL/6J-m+ Leprdb mice (db/db) and heterozygous (db/-) littermates and treated daily with normal saline or 2.5S NGF (1 microg/day or 10 microg/day) on post-injury days 0-6. Time to closure, wound epithelialization, and degree of inflammation were compared using a Student's t-test. Color subtractive-computer-assisted image analysis was used to quantify immunolocalized nerves in wounds. Non-overlapping (20x) digital images of the wound were analyzed for nerve profile counts, area density (number of protein gene product 9.5 positive profiles per unit dermal area) and area fraction (protein gene product 9.5 positive area per unit dermal area). Healing times in db/db mice decreased from 30 days in normal saline-treated mice to 26 days in mice treated with 1 microg/day NGF (p<0.05) and 24 days in mice treated with 10 microg/day NGF (p<0.02). A similar trend in db/- mice was not significant. NGF treatment augmented epithelialization in the db/db mice (p<0.05). Histological evaluation of inflammation in healed wounds showed no statistical difference between treatment groups. Total nerve number, area density, and area fraction were increased in NGF-treated wounds at 14, 21, and 35 days (p<0.05). The 2.5 NGF subunit may improve wound closure kinetics by promoting epithelialization and nerve regeneration. Further studies to determine the role of nerves in wound repair are warranted.     

含神经生长因子的几丁质管桥接兔面神经缺损的实验研究

目的 探讨含神经生长因子（ＮＧＦ）的几丁质管在修复兔面神经缺损中的作用。方法 将１６只新西兰兔的两侧面神经上颊支分别造成８ｍｍ的缺损,左侧用管腔内注入ＮＧＦ的几丁质管修复,右侧用自体神经移植修复作对照。术后８、１６周,分别取８只兔进行电生理和超微结构研究。结果 实验侧术后８周,再生神经中有髓和无髓神经纤维排列整齐,有髓神经的髓鞘厚,板层结构清晰;术后１６周,再生神经中有髓和无髓神经纤维数量增加,形     

Nerve growth factor: increased angiogenesis without improved nerve regeneration.

Nerve growth factor (NGF) and laminin are important factors for neural development and regeneration. We examined the effects of increasing the local concentration and duration of action of NGF and laminin on peripheral nerve regeneration in the adult mouse sciatic nerve. A Silastic (silicone rubber) channel with intraluminal NGF solution was secured between transected nerve ends. The second channel tested, formed from a polysaccharide called chitosan, was prepared with NGF and laminin in the channel walls and provided a sustained release of NGF. At six weeks post-implantation, no improvement in nerve regeneration was identified in those channels prepared with NGF when comparing electromyographic thresholds (microA), maximum potentials (mV), nerve diameter, myelin sheath thickness, myelinated axon counts, or diameter. However, increased angiogenesis was demonstrated within the chitosan and Silastic channels prepared with NGF compared to those channels without NGF. Silastic exhibited minimal inflammation. Chitosan was associated with inflammation in many nerve channels.