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1.
Oxidative stress has a key role in the pathogenesis of diabetic complications. We have previously reported that taurine (T), which is known to counteract oxidative stress in tissues (lens, kidney, retina) of diabetic rats, attenuates nerve blood flow and conduction deficits in early experimental diabetic neuropathy (EDN). The purpose of this study was to evaluate whether dietary T supplementation counteracts oxidative stress and the nerve growth factor (NGF) deficit in the diabetic peripheral nerve. The experiments were performed in control rats and streptozotocin‐diabetic rats fed standard or 1% T‐supplemented diets for 6 weeks. All measurements were performed in the sciatic nerve. Malondialdehyde (MDA) plus 4‐hydroxyalkenals (4‐HA) were quantified with N‐methyl‐2‐phenylindole. GSH, GSSG, dehydroascorbate (DHAA), and ascorbate (AA) were assayed spectrofluorometrically, T by reverse‐phase HPLC, and NGF by ELISA. MDA plus 4‐HA concentration (mean +/? SEM) was increased in diabetic rats (0.127 +/?0.006 vs 0.053 +/?0.003 mu mol/g in controls, P<0.01), and this increase was partially prevented by T (0.0960.004, P<0.01 vs untreated diabetic group). GSH levels were similarly decreased in diabetic rats treated with or without taurine vs controls. GSSG levels were similar in control and diabetic rats but were lower in diabetic rats treated with T (P<0.05 vs controls). AA levels were decreased in diabetic rats (0.133+0.015 vs 0.219 +/?0.023 mu mol/g in controls, P<0.05), and this deficit was prevented by T. DHAA/AA ratio was increased in diabetic rats vs controls (P<0.05), and this increase was prevented by T. T levels were decreased in diabetic rats (2.7 +/?0.16 vs 3.8 +/?0.1 mu mol/g in controls, P<0.05) and were repleted by T supplementation (4.20.3). NGF levels were decreased in diabetic rats (2.35 +/?0.20 vs 3.57 +/?0.20 ng/g in controls, P<0.01), and this decrease was attenuated by T treatment (3.160.28, P<0.05 vs diabetic group). In conclusion, T counteracts oxidative stress and the NGF deficit in early EDN. Antioxidant effects of T in peripheral nerve are, at least in part, mediated through the ascorbate system of antioxidative defense. The findings are consistent with the important role for oxidative stress in impaired neurotrophic support in EDN.  相似文献   

2.
Oxidative stress has a key role in the pathogenesis of diabetic complications. We have previously reported that taurine (T), which is known to counteract oxidative stress in tissues (lens, kidney, retina) of diabetic rats, attenuates nerve blood flow and conduction deficits in early experimental diabetic neuropathy (EDN). The purpose of this study was to evaluate whether dietary T supplementation counteracts oxidative stress and the nerve growth factor (NGF) deficit in the diabetic peripheral nerve. The experiments were performed in control rats and streptozotocin-diabetic rats fed standard or 1% T-supplemented diets for 6 weeks. All measurements were performed in the sciatic nerve. Malondialdehyde (MDA) plus 4-hydroxyalkenals (4-HA) were quantified with N-methyl-2-phenylindole. GSH, GSSG, dehydroascorbate (DHAA), and ascorbate (AA) were assayed spectrofluorometrically, T by reverse-phase HPLC, and NGF by ELISA. MDA plus 4-HA concentration (mean +/- SEM) was increased in diabetic rats (0.127 +/- 0.006 vs 0.053 +/- 0.003 micromol/g in controls, P < 0.01), and this increase was partially prevented by T (0.096 +/- 0.004, P < 0.01 vs untreated diabetic group). GSH levels were similarly decreased in diabetic rats treated with or without taurine vs controls. GSSG levels were similar in control and diabetic rats but were lower in diabetic rats treated with T (P < 0.05 vs controls). AA levels were decreased in diabetic rats (0.133 +/- 0.015 vs 0.219 +/- 0.023 micromol/g in controls, P < 0.05), and this deficit was prevented by T. DHAA/AA ratio was increased in diabetic rats vs controls (P < 0.05), and this increase was prevented by T. T levels were decreased in diabetic rats (2.7 +/- 0.16 vs 3.8 +/- 0.1 micromol/g in controls, P < 0.05) and were repleted by T supplementation (4.2 +/- 0.3). NGF levels were decreased in diabetic rats (2.35 +/- 0.20 vs 3.57 +/- 0.20 ng/g in controls, P < 0.01), and this decrease was attenuated by T treatment (3.16 +/- 0.28, P < 0.05 vs diabetic group). In conclusion, T counteracts oxidative stress and the NGF deficit in early EDN. Antioxidant effects of T in peripheral nerve are, at least in part, mediated through the ascorbate system of antioxidative defense. The findings are consistent with the important role for oxidative stress in impaired neurotrophic support in EDN.  相似文献   

3.
糖尿病周围神经病变患者神经病理及临床研究   总被引:35,自引:1,他引:34  
目的 探讨糖尿病神经病变患者临床与神经病理变化的相关性。方法 观察非胰岛素依赖型糖尿病神经病变症状、体征,同时进行血糖、果糖胺、红细胞山梨醇及神经传导速度(NCU)测定,并做腓肠神经病理检查。结果 10例患者血糖、果糖胺及红细胞山梨醇明显增高,NCU下降,以感觉NCU下降明显。神经病理显示不同程度神经纤维减少、轴索变性及血管狭窄。结论 糖尿病病程、代谢紊乱控制程度与NCU及神经病理损伤程度有一定相  相似文献   

4.
Hyperglycemia-induced oxidative stress is an inciting event in the development of diabetic complications including diabetic neuropathy. Our observations of significant oxidative stress and morphological abnormalities in mitochondria led us to examine manganese superoxide dismutase (SOD2), the enzyme responsible for mitochondrial detoxification of oxygen radicals. We demonstrate that overexpression of SOD2 decreases superoxide (O(2)(-)) in cultured primary dorsal root ganglion (DRG) neurons and subsequently blocks caspase-3 activation and cellular injury. Underexpression of SOD2 in dissociated DRG cultures from adult SOD2(+/-) mice results in increased levels of O2-, activation of caspase-3 cleavage and decreased neurite outgrowth under basal conditions that are exacerbated by hyperglycemia. These profound changes in sensory neurons led us to explore the effects of decreased SOD2 on the development of diabetic neuropathy (DN) in mice. DN was assessed in SOD2(+/-) C57BL/6J mice and their SOD2(+/+) littermates following streptozotocin (STZ) treatment. These animals, while hyperglycemic, do not display any signs of DN. DN was observed in the C57BL/6Jdb/db mouse, and decreased expression of SOD2 in these animals increased DN. Our data suggest that SOD2 activity is an important cellular modifier of neuronal oxidative defense against hyperglycemic injury.  相似文献   

5.
The mechanism/s leading to diabetic neuropathy are complex. Transforming growth factor-β1 (TGF-β1) has been associated with diabetic nephropathy and retinopathy but not neuropathy. In this study, changes in TGF-β isoforms were examined in vivo and in vitro. Two groups of animals, streptozotocin diabetic with neuropathy and non-diabetic controls were examined at 4 weeks (n = 10/group) and 12 weeks (n = 8/group). In diabetic DRG using quantitative real-time PCR (QRT-PCR), TGF-β1 and TGF-β2 mRNA, but not TGF-β3, was increased at 4 and 12 weeks. In sciatic nerve TGF-β3 mRNA was primarily increased. Immunohistochemistry (DRG) and immunoblotting (sciatic nerve) showed similar differential protein expression. In sciatic nerve TGF-β formed homo- and hetero-dimers, of which β23, β11, and β13 were significantly increased, while that of the TGF-β22 homodimer was decreased, in diabetic compared to non-diabetic rats. In vitro, pretreatment of embryonic DRG with TGF-β neutralizing antibody prevents the increase in total TGF-β protein observed with high glucose using immunoblotting. In high glucose conditions, combination with TGF-β2 > β1 increases the percent of cleaved caspase-3 compared to high glucose alone and TGF-β neutralizing antibody inhibits this increase. Furthermore, consistent with the findings in diabetic DRG and nerve, TGF-β isoforms applied directly in vitro reduce neurite outgrowth, and this effect is partially reversed by TGF-β neutralizing antibody. These findings implicate upregulation of TGF-β in experimental diabetic peripheral neuropathy and indicate a novel mechanism of cellular injury related to elevated glucose levels. In combination, these findings indicate a potential new target for treatment of diabetic peripheral neuropathy.  相似文献   

6.
H-反射对糖尿病近段神经病的诊断作用   总被引:9,自引:0,他引:9  
目的证实糖尿病近段神经病的存在以及H反射在糖尿病近段神经病中的诊断作用。方法通过经典的H反射和顺向周围神经传导检测方法,对正常组176条胫神经、糖尿病组268条胫神经进行对比研究。正常胫神经H波潜伏期(HL)多元回归方程8.2+0.5×腿长(cm)+0.06×年龄(岁),再加3.6ms(2s)为建议的正常参考值上限。结果44.0%(118/268)糖尿病组胫神经HL延长。糖尿病组胫神经中,74.6%(200/268)HL大于95%正常参考值上限,明显高于感觉神经传导速(38.5%)和运动神经传导速(43.3%)检测的阳性率(χ2=115.6,P<0.0001)。结论H反射较常规周围神经传导检测具有更高的诊断敏感性,糖尿病近段神经病的发生可能远较临床诊断的频度为高。  相似文献   

7.
8.
In rats with streptozotocin-induced diabetes, we measured increased (by 61%; P<0.05) mRNA for nerve growth factor (NGF) in the iris together with increased (by 82%; P<0.05) mRNA for preprotachykinin (the substance P precursor) in the trigeminal ganglion, suggesting that increased NGF was driving increased substance P gene expression. In other diabetic rats, these changes were prevented by treatment with either an antioxidant (butylated hydroxytoluene; 1% by diet) or an aldose reductase inhibitor (ARI) (sorbinil; 25 mg/kg/day p.o.) and the sorbinil treatment was associated with significant inhibition of polyol pathway intermediates in both lens and sciatic nerve. This suggests that polyol pathway activity in the lens may translate to oxidative stress-driving stimulation of NGF gene expression in the iris. The change is selective for NGF, because expression of the analogous neurotrophin, neurotrophin-3 (NT-3), was unaltered in the same irises. These changes suggest that oxidative stress and/or inflammation can drive up NGF expression in diabetes—a mechanism that might participate in iritis.  相似文献   

9.
Peripheral neuropathic alterations associated with diabetes and its treatment with insulin were studied in alloxan-induced diabetic rats. Treatment regimens included daily injections of Protamine Zinc Insulin (PZI), daily injections of Ultralente Insulin and subcutaneously implanted osmotic minipump delivered insulin. Non-diabetic and untreated diabetic groups served as controls. Two separate but similar studies were run, one lasting 4 weeks and the other 8 weeks. Conduction velocities performed on both sensory and motor nerves revealed no statistically significant differences among groups. Anatomical analysis of teased fibers from tibial nerves showed a significant number of fibers with ovoids, consistent with Wallerian-type axonal degeneration, only in the treated diabetic groups. Degeneration was especially severe in the PZI-treated group. Metabolic studies were performed using incorporation of radioactive isotopes ([3H]fucose, [14C]leucine) into myelin proteins of sciatic nerves. The ratio of [3H]fucose[14C]leucine for the PZI-treated group was significantly decreased when compared to the control groups in both the 4 and 8 week study whereas the minipump-treated group showed no statistically significant difference from the control group in either study. Similar decreases in this ratio have been seen in conditions of peripheral nerve degeneration. It is concluded that daily injections of PZI insulin result in significant nerve degeneration in the alloxan diabetic rat, while continuous levels of insulin delivered by osmotic minipumps result in less degeneration.  相似文献   

10.
In the experimental rat model of diabetes a slowing of nerve conduction velocity and a resistance to ischemic conduction failure have been found as an indication of polyneuropathy. The same electrophysiological abnormalities have been demonstrated in a model in which healthy rats are kept under hypoxic conditions (10% O2) for a 10-week period. Two factors are held responsible for the development of diabetic polyneuropathy: metabolic deterioration and hypoxia. However, until now the relative roles of metabolic deterioration and hypoxia in the development of polyneuropathy have not been settled. To test both explanations further with more sophisticated electrophysiological techniques, the H-reflex (motor and sensory NVC) and the stimulated SF-EMG (measures terminal nerve branch and neuromuscular transmission) were measured in 3 groups of 10 rats, a healthy control group, a diabetic group, and a hypoxic group, every 5 weeks, for 6 months. In the control rats an age-related increase in motor and sensory conduction velocity was found, whereas in the diabetic rats as well as in the hypoxic rats a marked decrease in sensory and a slight decrease in motor nerve conduction velocity was observed. The jitter measured in the stimulated SF-EMG was significantly increased in both the diabetic and the hypoxic group. The results of the present study support the possible role of hypoxia, in addition to metabolic factors, in the development of experimental diabetic neuropathy.  相似文献   

11.
目的 探讨神经生长因子对糖尿病周围神经病变大鼠神经肽和神经传导速度的影响. 方法 雄性Wistar大鼠35只按随机数字表法分为健康对照组(n=10)、糖尿病模型组(n=13)和神经生长因子治疗组(n=12),后两组用链脲佐菌素制成糖尿病周围神经病变大鼠模型,并给予神经生长因子治疗组神经生长因子治疗(40μg/kg).显微镜下观察并计算背根神经节中P物质、降钙素基因相关肽(CGRP)免疫阳性细胞率,检测运动神经传导速度(MNCV)和感觉神经传导速度(SNCV). 结果 糖尿病模型组大鼠背根神经节中P物质、CGRP免疫阳性细胞率(27.710%±3.471%;36.360%±12.027%)以及神经生长因子治疗组治疗前MNCV [(35.80±6.19) m/s]、SNCV[(39.62±6.69) m/s]与健康对照组[P物质:44.225%±8.213%;CGRP:47.400%±13.723%;MNCV:(55.83±10.30) m/s; SNCV:(47.02±7.52) m/s]相比显著下降,差异有统计学意义(P<0.05).经神经生长因子治疗后,P物质、CGRP免疫阳性细胞率(49.417%±6.753%;53.811%±7.125%)较糖尿病模型组显著增高,MNCV[(41.80±3.45) m/s]、SNCV[(42.92±6.69) m/s]均治疗前显著增高,差异有统计学意义(P<0.05). 结论 糖尿病周围神经病变大鼠可出现神经传导速度下降和神经生长因子相关神经肽P物质、CGRP缺乏,而神经生长因子可促进神经肽的表达并提高神经传导速度.  相似文献   

12.
Clinical studies suggest that impaired glucose tolerance (IGT) is associated with the development of neuropathy. The aim of the current study was to determine if neuropathy developed in the female Zucker Diabetic Fatty (ZDF) rat, an animal model of IGT and type 2 diabetes. The ZDF rat develops impaired glucose tolerance (IGT) when fed a control diet, and frank diabetes when fed a high fat diet. Following 10 weeks of hyperglycemia, sensory nerve action potentials (SNAP) and compound motor action potentials (CMAP) were reduced and sensory conduction velocities were slowed (distal > proximal) in the tail and hind limb in ZDF animals with IGT and frank diabetes (p < 0.01). Neuropathy was coupled with evidence of increased reactive oxygen species (ROS) and cellular injury in dorsal root ganglion (DRG) neurons from IGT animals. Our study supports the hypothesis that neuropathy develops in an animal model of IGT and is associated with evidence of oxidative injury in DRG and peripheral nerves.  相似文献   

13.
Nicotine dependence is common in people with mood disorders; however the operative pathways are not well understood. This paper reviews the contribution of inflammation and oxidative stress pathways to the co-association of depressive disorder and nicotine dependence, including increased levels of pro-inflammatory cytokines, increased acute phase proteins, decreased levels of antioxidants and increased oxidative stress. These could be some of the potential pathophysiological mechanisms involved in neuroprogression. The shared inflammatory and oxidative stress pathways by which smoking may increase the risk for development of depressive disorders are in part mediated by increased levels of pro-inflammatory cytokines, diverse neurotransmitter systems, activation the hypothalamic–pituitary–adrenal (HPA) axis, microglial activation, increased production of oxidative stress and decreased levels of antioxidants. Depressive disorder and nicotine dependence are additionally linked imbalance between neuroprotective and neurodegenerative metabolites in the kynurenine pathway that contribute to neuroprogression. These pathways provide a mechanistic framework for understanding the interaction between nicotine dependence and depressive disorder.  相似文献   

14.
Methylmalonic acidemia (MMA) is the most common organic acidemia in childhood. Many “treated” patients continued to display various degrees of mental retardation and psychomotor delay, which could be caused by brain damage from elevated oxidative stress. Aminoguanidine (AG), a synthetic antioxidant, was tested in a MMA rat model for its potential therapeutic effects on memory impairment. The effects of AG on MMA-induced cognitive impairment in Wistar rats were evaluated with Morris Water Maze. The levels of nerve cell apoptosis and microglial activation were investigated to illustrate the mechanisms of the improvement of cognition with AG treatment in MMA rats. To further explore the mechanism of neuroprotection induced by AG, several biomarkers including free radicals and inflammatory cytokines in the hippocampus were quantified. The results showed that the rats treated with AG exhibited better neurological behavior performances than MMA model rats. The AG-treated rats had a decreased level of apoptosis of the hippocampal neurons, which could be the structural basis of the observed neural behavior protection. In addition, AG treatment significantly inhibited the activation of microglia. The AG-treated rats had decreased levels of IL-1β, IL-6, TNF-α, NO, malonaldehyde and iNOS activities in the hippocampus. The level of glutathione and superoxide dismutase activity in the hippocampus of the AG-treated rats increased significantly. In conclusion, AG could alleviate the MMA-induced cognitive impairment via down-regulating of oxidative stress and inflammatory reaction and provide a basis as a therapeutic potential against MMA-induced cognitive impairment.  相似文献   

15.
Low serum levels of nerve growth factor in diabetic neuropathy   总被引:7,自引:0,他引:7  
Several structural and functional similarities between nerve growth factor and insulin have been described. Diabetes mellitus, a disease with absolute or relative deficiency of insulin is frequently associated with peripheral neuropathy whose physiopathological mechanisms are obscure. In this study, we measured serum levels of NGF in 18 patients with diabetic neuropathy and 9 healthy controls; patients with diabetic neuropathy had lower levels of NGF than controls (p less than 0.01). When patients were separated in two groups according to degree of impairment of motor nerve conduction velocity, those with more than 10% of impairment, had lower levels of NGF than those with less than 10% of impairment, or controls. It was found a correlation between NGF levels and decrease of motor nerve conduction velocity; then, diabetic neuropathy seems to be associated to low serum levels of NGF, pointing out a possible role of NGF in the pathology of diabetic neuropathy.  相似文献   

16.
目的探讨影响老年糖尿病痛性神经病变患者治疗效果的因素,并提出相应的干预措施。方法选取老年糖尿病痛性神经病变患者581例,随机分为2组,对所有患者的临床资料进行回顾分析。结果治疗无效患者中年龄≥70岁、FBG6.1mmol/L、HbA1c≥8.2%、单纯口服药物治疗以及治疗前疼痛程度为轻中度者明显多于治疗显效或有效的患者(P0.05)。经过Logistic回归分析,年龄≥70岁、FBG6.1mmol/L、HbA1c≥8.2%、单纯口服药物治疗是影响老年糖尿病痛性神经病变的独立危险因素(P0.05)。结论影响老年糖尿病痛性神经病变治疗效果的因素包括治疗方法的选择、年龄、血糖控制情况等,临床工作中应给予高龄患者更多关注,同时积极控制血糖水平,选择适宜治疗方法,给予必要的心理辅导,指导患者正确认识治疗效果。  相似文献   

17.
Introduction: A case series of acute intermittent porphyria (AIP) is described that focuses on the clinical course of the disease with regard to neurological manifestations of the peripheral nervous system. Methods: Eight patients were diagnosed with AIP on the basis of characteristic clinical findings, erythrocyte porphobilinogendeaminase activity, neuropathic patterns, serial changes in nerve conduction studies (NCS), and temporal relationship of central nervous system involvement. Results: Six patients diagnosed with AIP <2 months after symptom onset had neuropathy that was predominantly upper extremity, motor, and proximal. NCS recovery rates were slower in the lower than the upper limbs. Two patients diagnosed >2 months after symptom onset had distal sensorimotor polyneuropathy. Conclusions: The findings from this case series suggest that the peripheral nerves may be differentially and selectively involved in different diagnostic stages of porphyric neuropathy. Muscle Nerve 51 : 363–369, 2015  相似文献   

18.
氧化应激(Oxidative Stress)不仅在糖尿病、高血压病等身心疾病中起着重要作用,而且对阿尔茨海默病(AlzheimerDisease,AD)、帕金森病(Parkin-son Disease,PD)等神经精神障碍的认知功能也有一定影响。强烈或持续性的氧化应激可通过诱导细胞凋亡和炎性反应导致细胞、组织损害。流行病学及动物研究均表明,母孕期遭受应激可能会影响胎儿的神经心理发育过程,造成胎儿大脑某区域的缺陷,引起持续性认知改变、神经内分泌和行为反应,增加后代精神疾病的患病风险。现对氧化应激与认知功能障碍的机制进行综述。  相似文献   

19.
Ifosfamide (IFA), a commonly used chemotherapeutic drug, has been frequently associated with encephalopathy and central nervous system toxicity. The present study aims to investigate whether morin could protect against acute IFA-induced neurotoxicity. Morin was administered to male rats once daily for 2 consecutive days at doses of 100 and 200 mg/kg body weight (BW) orally. IFA (500 mg/kg BW; i.p.) was administered on second day. The results showed that morin markedly inhibited the production of acetylcholinesterase (AChE), butrylcholinesterase (BChE), carbonic anhydrase (CA), glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf-2) induced by IFA. Morin ameliorated IFA-induced lipid peroxidation, glutathione (GSH) depletion, and decrease antioxidant enzyme activities, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Histopathological changes and immunohistochemical expressions of c-Jun N-terminal kinase (JNK) and c-Fos in the IFA-induced brain tissues were decreased after administration of morin. Furthermore, morin was able to down regulate the levels of inflammatory and apoptotic markers such as nuclear factor kappa B (NF-κB), neuronal nitric oxide synthase (nNOS), tumor necrosis factor-α (TNF-α), p53, cysteine aspartate specific protease-3 (caspase-3) and B-cell lymphoma-2 (Bcl-2). Taken together, our results demonstrated that morin elicited a typical chemoprotective effect on IFA-induced acute neurotoxicity.  相似文献   

20.
The decline in cognitive ability and physical performance in older adults with intellectual disabilities (ID) is accompanied by less participation in social activities and a sedentary lifestyle; however the pathogenesis is not clear yet. It was recently suggested that chronic disease, adverse drug reactions, and aging create a cascade of events that can be best characterized as an asymptomatic inflammatory process. This cascade of events is mediated by cytokine interleukins 1 and 6 (IL-1α, and IL-6), nitric oxide (NO) and total oxidative stress (OS). Our hypothesis was that chronic inflammation in the bloodstream of persons with ID contributes to their “premature aging”. To test this hypothesis, we measured and compared the levels of inflammatory molecules in persons with and without ID. Fifteen adults with, and 15 adults without ID (control group) participated in this study. The levels of NO metabolites (NOx), IL-1α, and IL-6 were obtained from participants’ serum. OS markers were drawn from participants’ capillary. Western blot, RT-PCR and specific chemical analysis were used as measurement tools. The levels of inflammatory molecules and OS were significantly higher in persons with ID compared to the control group. Asymptomatic inflammation in the bloodstream of the older adults with ID might explain the “premature aging” of these individuals. Monitoring the levels of inflammatory molecules could serve as biomarkers of “premature aging” which may allow early diagnosis and intervention, and improve the quality of care for persons with ID.  相似文献   

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