糖尿病大鼠周围神经bFGF的动态表达及巴曲酶对其的影响

目的探讨碱性成纤维生长因子(bFGF)在糖尿病周围神经病(DPN)大鼠中的动态变化规律;观察巴曲酶对bFGF的影响及其机制,为临床上治疗DPN提供理论依据。方法将大鼠腹腔注射链脲佐菌素制作实验性糖尿病模型,分别于成模后2m和3m时腹腔注射巴曲酶进行干预。通过免疫组织化学和原位杂交双重检测bF-GF在坐骨神经中的表达。结果DM造模后2m时坐骨神经中bFGF的含量明显减少,且随时间变化有统计学差异,巴曲酶治疗后bFGF的表达明显增加。结论DPN大鼠坐骨神经中bFGF表达减少可能参与DPN的发病机制。巴曲酶对DPN有保护作用,其机制可能包括对bFGF的调节。     

糖尿病大鼠周围神经IGF-1及VEGF的动态表达及巴曲酶对其的影响

目的 探讨胰岛素样生长因子(IGF-1)及血管内皮生长因子(VEGF)在糖尿病周围神经病(DPN)大鼠中的动态变化规律及巴曲酶对IGF-1和VEGF的影响并探讨其机制,为临床治疗DPN提供理论依据.方法 大鼠腹腔注射链脲佐菌素制作实验性糖尿病模型,分别于成模后2m和3m时腹腔注射巴曲酶进行干预.通过免疫组织化学和原位杂交双重检测IGF-1及VEGF在坐骨神经中的表达.结果 DM造模后2m时坐骨神经中IGF-1及VEGF的含量均明显减少,且随时间变化有统计学差异,而巴曲酶治疗后IGF-1的表达无明显改变,VEGF的表达明显增加.结论 :DPN大鼠坐骨神经中IGF-1及VEGF表达减少可能参与DPN的发病机制,而巴曲酶对DPN的保护作用,并非通过对IGF-1的调节,其机制可能包括对VEGF的调节.     

糖尿病周围神经病动物模型的建立、病理观察及巴曲酶保护作用研究

目的建立稳定、可靠的糖尿病周围神经病（DPN）动物模型，观察坐骨神经的病理改变及检测周围神经传导速度和血液流变性等指标，观察巴曲酶是否对DPN有保护作用。方法将大鼠腹腔注射链脲佐菌素制作实验性糖尿病模型，再分别于成模后2个月和3个月时腹腔注射巴曲酶进行干预。电镜、光镜下观察坐骨神经的病理改变，同时检测周围神经传导速度和血液流变件等指标。结果糖尿病大鼠自造模后2个月开始，周围神经传导速度明显减慢，血液粘度及血浆粘度明显升高，用巴曲酶治疗后均得以明显改善，但神经传导速度仍低于正常。血液流变学中仅低切速血液粘度随病程延长而增加，其它指标与病程无关。光镜下可见糖尿病大鼠坐骨神经纤维髓鞘密度不均匀，有斑块状密度减低区。电镜下可见糖尿病大鼠髓鞘局部增厚及板层分离，治疗后上述改变均减轻，细小神经纤维明显增生。结论腹腔注射链脲佐菌素法可建立可靠的实验性DPN动物模型，巴曲酶干预后血液流变性得以改善，周围神经病理改变得以减轻，说明巴曲酶对DPN有保护作用。     

人神经生长因子对DPN大鼠坐骨神经CGT的作用

目的　观察人神经生长因子 ( h NGF)对早期糖尿病多发性神经病 ( DPN)大鼠坐骨神经中半乳糖神经酰胺转移酶 m RNA( CGTm RNA)表达的影响。方法　用链脲佐菌素 ( STZ)一次性腹腔注射诱导糖尿病大鼠模型 ,在 DPN 4周 (造模后 4周 )腹腔注射 h NGF( 90 U .kg- 1 .d- 1 ) ,共 4周。用 RT- PCR和免疫组化方法观察坐骨神经CGTm RNA,NGFm RNA和蛋白表达。结果　 DPN 8周大鼠坐骨神经 CGTm RNA升高 ,NGFm RNA和蛋白表达减少。用 h NGF治疗的 DPN大鼠 CGTm RNA明显降低 ,NGFm RNA和蛋白表达增加。结论　 h NGF治疗能纠正早期DPN大鼠坐骨神经 CGTm RNA异常     

巴曲酶对糖尿病周围神经病大鼠血液流变性的影响

目的探讨巴曲酶对糖尿病周围神经病大鼠血液流变性的作用。方法用链尿佐菌素一次性腹腔注射诱导糖尿病大鼠模型,在造模后2月和3月时腹腔注射巴曲酶8Bu/(kg·d),10d后测定坐骨神经运动及感觉神经传导速度;然后取血测定其血液流变学指标。结果糖尿病大鼠在造模后2月和3月时周围神经传导速度明显减慢,血液流变学指标明显增加,用巴曲酶治疗后均明显改善。结论巴曲酶治疗糖尿病周围神经病的机制之一可能为改善其血液流变学。     

巴曲酶对实验性糖尿病大鼠周围神经传导速度的影响

目的探讨巴曲酶对糖尿病大鼠周围神经传导速度的作用。方法用链脲佐菌素一次性腹腔注射诱导糖尿病大鼠模型,在造模后2月和3月时腹腔注射巴曲酶8Bu/(kg·d),10d后测定坐骨神经运动及感觉神经传导速度。结果糖尿病大鼠在造模后2月和3月时周围神经传导速度明显减慢;用巴曲酶治疗的糖尿病大鼠周围神经传导速度明显加快。结论巴曲酶治疗能纠正糖尿病大鼠周围神经传导速度的异常。     

人神经生长因子对糖尿病多发性神经病大鼠坐骨神经caloainⅡ的作用

目的:观察人神经生长因子(hNGF)对早期糖尿病多发性神经病(DPN)大鼠坐骨神经中calpainⅡ表达的影响。方法:用链佐星(STZ)一次性腹腔注射诱导糖尿病大鼠模型,在DPN4周(造模后4周)腹腔注射hNGF90U/(kg·d),共4周。用原位杂交和免疫组化方法观察坐骨神经calpainⅡmRNA和蛋白表达。结果:DPN8周大鼠坐骨神经calpainⅡmRNA和蛋白表达明显减少。用hNGF治疗的DPN大鼠calpainⅡmRNA和蛋白表达增加。结论:hNGF治疗能纠正早期DPN大鼠坐骨神经calpainⅡmRNA和蛋白表达异常。     

依达拉奉对糖尿病周围神经病大鼠神经保护的机制

目的 探讨依达拉奉对糖尿病周围神经病(DPN)大鼠神经保护的机制.方法 采用链脲佐菌素(STZ)一次性腹腔注射诱导建立SD大鼠DPN模型,并随机分为对照组和治疗组(各10只);治疗组给予依达拉奉3 mg/(kg·d)腹腔注射共4周.观察摆尾温度阈值(TTT)、坐骨神经运动神经传导速度(MCV)、感觉神经传导速度(SCV);应用酶标法及免疫组化法分别检测坐骨神经半胱氨酸蛋白酶( caspase)-3和Bcl-2表达水平,并与正常组(10只)比较.结果 与正常组比较,对照组大鼠TTT明显升高,MCV和SCV明显减慢,坐骨神经caspase-3和Bcl-2表达水平明显增高(均P＜0.01);与对照组比较,治疗组大鼠TTT明显降低,MCV和SCV明显提高(均P＜0.01);坐骨神经caspase-3表达水平明显降低,Bcl-2表达水平明显增高(均P＜0.05).结论 依达拉奉可以减轻DPN大鼠坐骨神经损伤,其机制可能与其降低周围神经caspase-3表达和增强Bcl-2表达有关.     

神经生长因子对脑梗死大鼠血清S-100β蛋白与神经元特异性烯醇化酶含量的影响

目的探讨鼠神经生长因子（nerve growth factor,NGF）治疗对脑梗死大鼠血清S-100β蛋白与神经元烯醇化酶（NSE）表达水平的影响。方法将大鼠随机分为模型组及NGF治疗组,建立MCAO大鼠模型,腹腔注射NGF,采用酶联免疫吸附法对脑梗死大鼠起病第1、3、7天血清S-100β蛋白与NSE水平进行动态测定。结果模型组大鼠血清S-100β蛋白与NSE浓度在起病第1、3、7天均显著升高,NGF治疗组大鼠经NGF治疗后其表达水平明显下降,与模型组比较,差异有统计学意义（P〈0.01）。结论 NGF可以显著减轻脑梗死大鼠的神经损伤,这可能是其神经保护作用的机制之一。     

中枢类大麻受体拮抗剂利莫那班对2型糖尿病周围神经病变疗效的实验分析

目的 观察利莫那班对大鼠糖尿病周围神经痛变的疗效,探讨其作用机制.方法 采用链尿佐菌素(STZ)腹腔注射诱导形成糖尿病周围神经病变(DPN)模型,随机分为模型对照组、利莫那班小剂量组、利莫那班大剂量组、正常对照组.糖尿病大鼠造模成功后予利莫那班干预,开始给药24周后将模型组和正常组比较痛阈、坐骨神经传导速度.用酶联免疫吸附测定法(ELISA法)分别洲定各组大鼠血清、脊髓及坐骨神经内IL-Iβ、TNF-α的浓度.结果 利莫邢班对DNP大鼠痛阈、坐骨神经传导速度(NCV)有明显改善(P＜0.05).与对照组比较.DPN模型组大鼠的lL-Iβ、TNF-α的含量显著增高(P＜0.05),利莫那班治疗24周后.与DPN模型组比较IL-lβ、TNF-α的含量显著降低(P＜0.05).结论 利莫那班对糖尿病周围神经病变有良好的疗效,可能是通过调节自身免疫功能机制发挥作用.     

Altered immediate early gene expression in injured diabetic nerve: implications in regeneration

To study the role that immediate early gene responses may play in impaired nerve fiber regeneration in diabetes, diabetic male BB/Wor rats were subjected to sciatic nerve crush at 6 wk of diabetes. Sciatic nerve mRNA expression of IGF-I, IGF-1-receptor, NGF, and p75 (low affinity NGF receptor), as well as protein expression of C-FOS, were examined at various time points following crush injury and compared with age- and sex-matched nondiabetic BB/Wor rats. Diabetic rats showed a delay in the early peak expression of IGF-1, C-FOS, NGF, and p75. The earliest immediate gene responses were those of IGF-I and IGF-1-receptor, which peaked at 0.5 h post-crush in control rats. In diabetic rats, IGF-1 peaked at 24 h whereas IGF-1-receptor mRNA revealed no early peak. The early NGF mRNA expression showed a maximum response at 6 h and of p75 at 4 days post-crush in control rats, whereas in diabetic rats they occurred at 2 days and 6 days, respectively. C-FOS protein expression showed a maximum at 6 h in control rats and in diabetic animals an attenuated peak was present at 2 days. These data provide the first evidence that immediate early gene responses are delayed in diabetes following sciatic nerve crush injury. The delayed IGF-1 expression may affect C-FOS induction and may be responsible for the delay in the NGF response in diabetic rats. The delayed immediate early gene responses precede the previously described perturbed macrophage recruitment and delayed Wallerian degeneration in this type I model and provide a possible explanation for impaired nerve regeneration in diabetes.     

Improved neural microcirculation and regeneration after peripheral nerve decompression in DPN rats*

Objective: Recently, neural microcirculation and regeneration were regarded as critical factors in diabetic peripheral neuropathy (DPN) improvement. In the present study, we explored the cytological and molecular mechanisms how peripheral nerve decompression impaired nerve injury.

Methods: Forty-five male SD rats were established as the DPN model. HE staining was used to observe the morphology and distribution of microvessels. Transmission electron microscopy was applied to observe the morphology and distribution of Schwann cells. Immunohistochemical staining was performed to measure nerve growth factor (NGF), tyrosine kinase receptor A (TrkA) and growth-associated protein 43 (GAP-43) in the distal sciatic nerve.

Results: Distribution of microvessels and Schwann cells decreased in the DPN group (p < 0.05). NGF, TrkA and GAP-43 also decreased significantly in the DPN group (p < 0.05). NGF, TrkA, GAP-43 and distribution of microvessels and Schwann cells increased in the decompressed group (p < 0.05).

Discussion: In DPN rats, after nerves are compressed, microcirculation disturbance and hypoxia ischemia will happen, which cause decreased expression of NGF, TrkA and GAP-43. Finally, the self-healing function of compressed nerves is impacted. Conversely, nerve decompression can improve neural microcirculation and regeneration and change the former pathological process.     

Streptozotocin-induced diabetes causes metabolic changes and alterations in neurotrophin content and retrograde transport in the cervical vagus nerve.

Abnormal availability of neurotrophins, such as nerve growth factor (NGF), has been implicated in diabetic somatosensory polyneuropathy. However, the involvement of neurotrophins in diabetic neuropathy of autonomic nerves, particularly the vagus nerve which plays a critical role in visceral afferent and in autonomic motor functions, is unknown. To assess the effects of hyperglycemia on the neurotrophin content and transport in this system, cervical vagus nerves of streptozotocin (STZ)-induced diabetic rats were studied at 8, 16, and 24 weeks after the induction of diabetes. Elevations in vagus nerve hexose (glucose and fructose) and polyol levels (sorbitol), and their normalization with insulin treatment, verified that the STZ treatment resulted in hyperglycemia-induced metabolic abnormalities in the nerve. Neurotrophin (NGF and neurotrophin-3; NT-3) content and axonal transport were assessed in the cervical vagus nerves from nondiabetic control rats, STZ-induced diabetic rats, and diabetic rats treated with insulin. The NGF, but not the NT-3, content of intact vagus nerves from diabetic rats was increased at 8 and 16 weeks (but not at 24 weeks). Using a double-ligation model to assess the transport of endogenous neurotrophins, the retrograde transport of both NGF and NT-3 was found to be significantly reduced in the cervical vagus nerve at later stages of diabetes (16 and 24 weeks). Anterograde transport of NGF or NT-3 was not apparent in the vagus nerve of diabetic or control rats. These data suggest that an increase in vagus nerve NGF is an early, but transient, response to the diabetic hyperglycemia and that a subsequent reduction in neuronal access to NGF and NT-3 secondary to decreased retrograde axonal transport may play a role in diabetes-induced damage to the vagus nerve.     

外源性神经生长因子注射治疗对脑出血大鼠模型神经功能及VEGF和HMGB1表达水平的影响

目的 探讨神经生长因子(nerve growth factor,NGF)对脑出血(intracerebral hemorrhage,ICH)大鼠模型神经功能及血管内皮生长因子(vascular endothelial growth factor,VEGF)和高迁移率族蛋白1(high mobility group box-1 protein,HMGB1)表达水平的影响。方法 SD大鼠(60只)构建脑出血ICH模型,并随机分为对照组、模型组和治疗组,治疗组给予颅内NGF 1.0 μg血肿内注射1周后检测大鼠神经功能NSS评分; HE染色法观察血肿周围脑组织病理学改变; 采用TUNEL法检测神经细胞凋亡; 采用Western blot法检测NGF、VEGF和HMGB1蛋白的表达水平。结果 与模型组比较,治疗组大鼠NSS评分显著增高,脑组织含水量显著减少(P<0.05); 治疗组凋亡细胞数显著减少(P<0.05)。治疗组大鼠脑组织NGF和VEGF蛋白水平显著升高及HMGB1蛋白水平显著降低(P<0.05)。治疗组神经细胞肿胀程度、间隙及细胞核改变均较轻,周围炎症反应和病理学改变减轻。结论 外源性神经生长因子有助于改善脑出血大鼠的神经功能损伤,其机制可能通过上调VEGF和下调HMGB1来减轻脑水肿和神经细胞凋亡,从而产生神经保护作用。     

The regeneration of peripheral noradrenergic nerves after chemical sympathectomy in diabetic rats: effects of nerve growth factor

The study investigated the role of nerve growth factor (NGF) in the regeneration of noradrenergic nerves of the right atria from control and 8-week diabetic rats, after lesion caused by a single injection of 6-hydroxydopamine (6-OHDA, 100 mg/kg ip). This treatment caused a profound depletion of tissue noradrenaline (NA) of the right atria from both control and diabetic groups, followed by a progressive repletion that was not complete at 49 days. Immunoreactivity for the NGF receptors trkA and p75(NTR) was decreased and increased, respectively, between days 3 and 28 in right atria from diabetic rats and returned to pretreatment levels at day 49. Receptor levels were not significantly altered in controls. In contrast to tissue NA, at day 14 functional responses to electrical nerve stimulation of the right atria had completely returned to the pretreatment state in diabetic rats and were very close to normal in nondiabetic rats. NGF treatment (1 mg/kg, three times/week, for 2 weeks) increased tissue NA only in control rats; the pattern was similar after 6-OHDA. These findings are consistent with the hypothesis that NGF normally plays a role in the regulation of autonomic sympathetic nerves in the adult rat atrium and that mature and uninjured sympathetic neurons remain responsive to NGF. In injured noradrenergic neurons, NGF promotes regeneration in nondiabetic rats. The ability of NGF to promote regeneration of noradrenergic nerves is lost in diabetes and this may relate to the loss of trkA receptor on prejunctional nerve terminals after denervation.     

Effects of chronic alcohol consumption,withdrawal and nerve growth factor on neuropeptide Y expression and cholinergic innervation of the rat dentate hilus

Several studies have demonstrated the vulnerability of the hippocampal formation (HF) to chronic alcohol consumption and withdrawal. Among the brain systems that appear to be particularly vulnerable to the effects of these conditions are the neuropeptide Y (NPY)-ergic and the cholinergic systems. Because these two systems seem to closely interact in the HF, we sought to study the effects of chronic alcohol consumption (6 months) and subsequent withdrawal (2 months) on the expression of NPY and on the cholinergic innervation of the rat dentate hilus. As such, we have estimated the areal density and the somatic volume of NPY-immunoreactive neurons, and the density of the cholinergic varicosities. In addition, because alcohol consumption and withdrawal are associated with impaired nerve growth factor (NGF) trophic support and the administration of exogenous NGF alters the effects of those conditions on various cholinergic markers, we have also estimated the same morphological parameters in withdrawn rats infused intracerebroventricularly with NGF. NPY expression increased after withdrawal and returned to control values after NGF treatment. Conversely, the somatic volume of these neurons did not differ among all groups. On other hand, the expression of vesicular acetylcholine transporter (VAChT) was reduced by 24% in ethanol-treated rats and by 46% in withdrawn rats. The administration of NGF to withdrawn rats increased the VAChT expression to values above control levels. These results show that the effects of prolonged alcohol intake and protracted withdrawal on the hilar NPY expression differ from those induced by shorter exposures to ethanol and by abrupt withdrawal. They also suggest that the normalizing effect of NGF on NPY expression might rely on the NGF-induced improvement of cholinergic neurotransmission in the dentate hilus.     

Intrathecal administration of nerve growth factor delays GAP 43 expression and early phase regeneration of adult rat peripheral nerve

Whether nerve growth factor (NGF) promotes peripheral nerve regeneration in vivo, in particular in adults, is controversial. We therefore examined the effect of exogenous NGF on nerve regeneration and the expression of GAP 43 (growth-associated protein 43) in adult rats. NGF was infused intrathecally via an osmotic mini-pump, while control rats received artificial cerebrospinal fluid. Two days after the infusion was initiated, the right sciatic nerves were transected or crushed, and the animals allowed to survive for 3 to 11 days. The right DRG, the right proximal stump of the transected sciatic nerve, and the posterior horn of the spinal cord were examined by Western blotting, immunohistochemistry, and electron microscopy. GAP 43 immunoreactivity in the NGF-treated animals was significantly lower than in the aCSF-treated controls. Electron microscopy showed that the number of myelinated and unmyelinated axons decreased significantly in the NGF-treated rats as compared with the controls. These findings are indicative that exogenous NGF delayed GAP 43 induction and the early phase of peripheral nerve regeneration and supports the hypothesis that the loss of NGF supply from peripheral targets via retrograde transport caused by axotomy serves as a signal for DRG neurons to invoke regenerative responses. NGF administered intrathecally may delay the neurons' perception of the reduction of the endogenous NGF, causing a delay in conversion of DRG neurons from the normal physiological condition to regrowth state.