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Wang H, Fang J, Hu F, Li G, Hong HE. Seawater immersion aggravates sciatic nerve injury in rats. Exp Ther Med 2015; 9:1153-1160. [PMID: 25780402 PMCID: PMC4353802 DOI: 10.3892/etm.2015.2281] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 01/22/2015] [Indexed: 01/07/2023] Open
Abstract
The aim of the present study was investigate the impact of seawater immersion on peripheral nerve injury and the underlying mechanisms. A total of 234 specific pathogen-free Sprague-Dawley male rats were randomly divided into a sham group, injury control group and seawater immersion + injury group. The Sciatic Functional Index (SFI) was used to assess nerve function for 6 weeks after injury. Compound muscle action potentials were measured and hematoxylin and eosin (H&E) staining of nerve specimens was carried out at week 6. Levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in nerve tissues were measured by enzyme-linked immunosorbent assay (ELISA), and the expression levels of inducible nitric oxide synthase (iNOS) mRNA and protein were measured by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively. The SFI value in the seawater immersion + injury group after 6 weeks was lower than that in the injury control group (P<0.05). The compound muscle action potential in the seawater immersion + injury group had a prolonged latency, and the amplitude and nerve conduction velocity were decreased compared with those in the other groups (P<0.05). H&E staining demonstrated that nerve fiber regeneration was worse in the seawater immersion + injury group. The ROS and MDA levels in the seawater immersion + injury group were higher than those in the other groups (P<0.05). The expression levels of iNOS mRNA and protein gradually increased in the injury and seawater immersion + injury groups and peaked at 48 h after surgery. Immersion in seawater further aggravated sciatic nerve injury and led to worse neuronal recovery. The mechanism may be associated with oxidative stress.
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Affiliation(s)
- Haifeng Wang
- Department of Micro-Orthopedics, The People's Liberation Army Clinical College Affiliated with Anhui Medical University (The 105th Hospital of People's Liberation Army), Hefei, Anhui 230031, P.R. China
| | - Jian Fang
- Department of Orthopedics, The People's Liberation Army Clinical College Affiliated with Anhui Medical University (The 105th Hospital of People's Liberation Army), Hefei, Anhui 230031, P.R. China
| | - Feng Hu
- Department of Micro-Orthopedics, The People's Liberation Army Clinical College Affiliated with Anhui Medical University (The 105th Hospital of People's Liberation Army), Hefei, Anhui 230031, P.R. China
| | - Gewei Li
- Department of Orthopedics, The People's Liberation Army Clinical College Affiliated with Anhui Medical University (The 105th Hospital of People's Liberation Army), Hefei, Anhui 230031, P.R. China
| | - H E Hong
- Department of Orthopedics, The People's Liberation Army Clinical College Affiliated with Anhui Medical University (The 105th Hospital of People's Liberation Army), Hefei, Anhui 230031, P.R. China
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Park JM, Kim CK, Lee HC, Jung H, Choi KU, Hong SW, Lim DG, Baek WY, Kwak KH. Antiallodynic effects of vitamin C and vitamin E in chronic post-ischemia pain rat model. Korean J Anesthesiol 2013; 65:442-8. [PMID: 24363848 PMCID: PMC3866341 DOI: 10.4097/kjae.2013.65.5.442] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/13/2013] [Accepted: 09/22/2013] [Indexed: 12/30/2022] Open
Abstract
Background Recent research has shown that reactive oxygen species (ROS) play a significant role in the development and persistence of neuropathic pain through central sensitization via N-methyl-D-aspartate (NMDA) receptor activation. In the present study, we examined whether the intraperitoneal administration of vitamins C and E alone or together could alleviate mechanical allodynia in a chronic post-ischemia pain (CPIP) rat model. Methods Vitamins C and E were administered intraperitoneally to 48 male Sprague Dawley rats once per day for 3 days before hindpaw ischemia-reperfusion (I/R) injury was induced. On the third day, the CPIP rat model was produced by inducing ischemia in the left hindpaw by applying an O-ring for 3 h, followed by reperfusion. Three days after reperfusion, hindpaw mechanical allodynia was assessed by measuring the withdrawal response to von Frey filament stimulation. The rats were sacrificed immediately after behavioral testing to determine the phosphorylated NMDA receptor subunit 1 (pNR1) and extracellular-signal-regulated kinases (pERK) levels in the spinal cord. Results When the antioxidant vitamins C and E were administered intraperitoneally to CPIP rats, I/R injury-induced mechanical allodynia was attenuated, and pNR1 and pERK levels were decreased in the rat spinal cord. Additionally, the co-administration of both vitamins had an increased antiallodynic effect. Conclusions The reduced phosphorylated NR1 and ERK levels indicate that vitamins C and E inhibit the modulation of spinal cord neuropathic pain processing. Co-administration of vitamins C and E had a greater antiallodynic effect.
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Affiliation(s)
- Jun-Mo Park
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Chae Kyung Kim
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Hyung Chul Lee
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Hoon Jung
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Kwang-Uk Choi
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Seong Wook Hong
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Dong Gun Lim
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Woon-Yi Baek
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Kyung-Hwa Kwak
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
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Inkster ME, Cotter MA, Cameron NE. Treatment with the xanthine oxidase inhibitor, allopurinol, improves nerve and vascular function in diabetic rats. Eur J Pharmacol 2007; 561:63-71. [PMID: 17291486 DOI: 10.1016/j.ejphar.2006.12.029] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 12/14/2006] [Accepted: 12/21/2006] [Indexed: 12/12/2022]
Abstract
Several putative sources of reactive oxygen species could potentially contribute to diabetic neuropathy and vasculopathy. The aim was to assess the involvement of elevated xanthine oxidase activity. After 6 weeks of streptozotocin-diabetes, groups of rats were given 2 weeks of high-dose allopurinol treatment (50 and 250 mg/kg) to gauge the effect of maximal blockade of xanthine oxidase. In the final experiments, rats were subjected to sensory testing and, under butabarbital anaesthesia, measurements were made on nerve conduction velocities and neural tissue blood flow estimated by hydrogen clearance microelectrode polarography. Further groups were used to study detailed responses of the isolated mesenteric vascular bed after 4 weeks of diabetes and allopurinol (150 mg/kg) treatment. Diabetes caused 20% and 14% reduction in motor and sensory conduction velocity, which were 78% and 81% corrected by allopurinol treatment respectively, both doses giving similar results. Diabetic rats showed tactile allodynia and thermal hyperalgesia, which were completely corrected by allopurinol, whereas mechanical hyperalgesia was only 45% ameliorated. Sciatic nerve and superior cervical ganglion blood flow was halved by diabetes and allopurinol corrected this by approximately 63%. Mesenteric endothelium-dependent vascular responses to acetylcholine, which depend upon nitric oxide and endothelium derived hyperpolarizing factor, were attenuated by diabetes. Allopurinol treatment gave approximately 50% protection for both components. Thus, xanthine oxidase is an important source of reactive oxygen species that contributes to neurovascular dysfunction in experimental diabetes. Inhibition of xanthine oxidase could be a potential therapeutic approach to diabetic neuropathy and vasculopathy.
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Affiliation(s)
- Melanie E Inkster
- School of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
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Abstract
Diabetic peripheral neuropathy is the most common complication of long-standing diabetes mellitus which frequently results in clinically significant morbidities e.g. pain, foot ulcers and amputations. During its natural course it progresses from initial functional changes to late, poorly reversible, structural changes. Various interconnected pathogenetic concepts of diabetic neuropathy have been proposed based on metabolic and vascular factors, mostly derived from long-term hyperglycemia. These pathogenetic mechanisms have been targeted in several experimental and clinical trials. This review summarizes available, mainly morphological data from interventions designed to halt the progression or achieve the reversal of established diabetic neuropathy, which include the recovery of normoglycemia by pancreas or islet transplantation, polyol pathway blockade by aldose reductase inhibitors, mitigation of oxidative stress by the use of antioxidants or correction of abnormalities in essential fatty acid metabolism. Unfortunately, to date, no treatment based on pathogenic considerations has shown clear positive effects and thus early institution of optimal glycemic control remains the only available measure with proven efficacy in preventing or halting progression of diabetic neuropathy. Further experimental and clinical research employing objective reproducible parameters is clearly needed. Novel non-invasive or minimally invasive methods e.g. corneal confocal microscopy or epidermal nerve fiber counts may represent potentially useful instruments for the objective assessment of nerve damage and monitoring of treatment effects.
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Affiliation(s)
- Petr Boucek
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague 4, Czech Republic.
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Di Iorio A, Cherubini A, Volpato S, Sparvieri E, Lauretani F, Franceschi C, Senin U, Abate G, Paganelli R, Martin A, Andres-Lacueva C, Ferrucci L. Markers of inflammation, vitamin E and peripheral nervous system function: the InCHIANTI study. Neurobiol Aging 2005; 27:1280-8. [PMID: 16112778 PMCID: PMC2646090 DOI: 10.1016/j.neurobiolaging.2005.07.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Revised: 05/27/2005] [Accepted: 07/10/2005] [Indexed: 11/24/2022]
Abstract
BACKGROUND Aging of the peripheral nervous system is associated with several morphologic and functional changes, including a decrease of the nerve conduction velocity. There is evidence that these changes contribute to age-related-decline in muscle strength, sensory discrimination, and autonomic responses. The aim of this study was to characterize the decline in nerve conduction velocity in the peripheral nervous system over the aging process and to identify factors that, independent of age, affect nerve conduction velocity. METHODS We measured motor nerve conduction velocity of the right superficial peroneal nerve using a standard neurophysiologic technique in a population-based sample of subjects aged between 20 and 103 years old enrolled in the InCHIANTI study. RESULTS Average conduction velocities in the peripheral nerve decreased linearly with age in both sexes. We found that diabetes, cognitive impairment, uric acid, sIL-6R and alpha-tocopherol were significant predictors of nerve conduction velocity independently of the potential confounding effect of age, sex, sex x age interaction term, height, lymphocytes, neutrophils number, alpha1 and alpha2-globulin serum protein. CONCLUSIONS Our findings are consistent with the hypothesis that inflammation and inadequate antioxidant defenses are associated with accelerated decline of nerve conduction velocity over the aging process.
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Affiliation(s)
- Angelo Di Iorio
- Laboratory of Clinical Epidemiology, Department of Medicine and Sciences of Aging, University G. D'Annunzio, Via dei Vestini 5, 66013 Chieti Scalo, Italy.
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Cotter MA, Cameron NE. Effect of the NAD(P)H oxidase inhibitor, apocynin, on peripheral nerve perfusion and function in diabetic rats. Life Sci 2003; 73:1813-24. [PMID: 12888120 DOI: 10.1016/s0024-3205(03)00508-3] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Upregulation of vascular NAD(P)H oxidase has been considered an important source for elevated levels of reactive oxygen species that contribute to several cardiovascular disease states, including the vascular complications of diabetes mellitus. Previous studies have shown that treatment with antioxidants corrects impaired nerve function and blood flow in diabetic rats. The aim was to assess the degree of involvement of NAD(P)H oxidase in experimental diabetic neuropathy. To this end, after 6 weeks of untreated streptozotocin-diabetes, rats were treated for 2 weeks with the NAD(P)H oxidase, apocynin. Two high doses (15 and 100 mg/kg) were used to ensure that maximal effects were registered. Diabetes caused a 20% reduction in sciatic nerve motor conduction velocity, and a 14% deficit for sensory saphenous nerve. Apocynin treatment corrected these defects by 32% and 48%, respectively: there were no significant differences between the effects of the 2 doses. Sciatic nerve nutritive endoneurial perfusion was measured by hydrogen clearance microelectrode polarography. Blood flow and vascular conductance were 47% and 40% reduced by diabetes, respectively. Both doses of apocynin had similar effects, correcting the blood flow deficit by 31% and conductance by 47%. Thus, the data show that NAD(P)H oxidase contributes to the neurovascular deficits in diabetic rats. While only accounting for part of the elevated reactive oxygen species production in diabetes, this mechanism could provide a novel therapeutic candidate for further investigation in diabetic neuropathy and vasculopathy.
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Affiliation(s)
- M A Cotter
- Department of Biomedical Sciences, Institute of Medical Sciences, Aberdeen University, Foresterhill, AB25 2ZD Scotland, Aberdeen, UK
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van Dam PS. Oxidative stress and diabetic neuropathy: pathophysiological mechanisms and treatment perspectives. Diabetes Metab Res Rev 2002; 18:176-84. [PMID: 12112935 DOI: 10.1002/dmrr.287] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Increased oxidative stress is a mechanism that probably plays a major role in the development of diabetic complications, including peripheral neuropathy. This review summarises recent data from in vitro and in vivo studies that have been performed both to understand this aspect of the pathophysiology of diabetic neuropathy and to develop therapeutic modalities for its prevention or treatment. Extensive animal studies have demonstrated that oxidative stress may be a final common pathway in the development of diabetic neuropathy, and that antioxidants can prevent or reverse hyperglycaemia-induced nerve dysfunction. Most probably, the effects of antioxidants are mediated by correction of nutritive blood flow, although direct effects on endoneurial oxidative state are not excluded. In a limited number of clinical studies, antioxidant drugs including alpha-lipoic acid and vitamin E were found to reduce neuropathic symptoms or to correct nerve conduction velocity. These data are promising, and additional larger studies with alpha-lipoic acid are currently being performed.
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Affiliation(s)
- P Sytze van Dam
- Department of Internal Medicine and Endocrinology, University Medical Center, Utrecht, The Netherlands.
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van Dam PS, van Asbeck BS, Van Oirschot JF, Biessels GJ, Hamers FP, Marx JJ. Glutathione and alpha-lipoate in diabetic rats: nerve function, blood flow and oxidative state. Eur J Clin Invest 2001; 31:417-24. [PMID: 11380593 DOI: 10.1046/j.1365-2362.2001.00832.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Increased oxidative stress is considered to be a causal factor in the development of diabetic complications, among which peripheral neuropathy. The pathophysiology of nerve dysfunction in diabetes has been explained both by reduced endoneurial microcirculation and alterations in endoneurial metabolism. It is unclear whether antioxidants primarily improve nerve blood flow or normalise systemic or endoneurial oxidative metabolism. Therefore, we evaluated the effects of the antioxidants glutathione and alpha-lipoic acid on both nerve microcirculation and the antioxidative capacity and lipid peroxidation in experimentally diabetic rats. MATERIALS AND METHODS Streptozotocin-diabetic rats were treated with different doses of alpha-lipoic acid, reduced glutathione or placebo, and were compared with nondiabetic controls. We measured systemic and endoneurial antioxidants, malondialdehyde and whole blood hydrogen peroxide. Furthermore, we evaluated sciatic and tibial motor and sensory nerve conduction velocity, caudal nerve conduction velocity, and assessed sciatic nerve blood flow and vascular resistance by Laser-Doppler flowmetry. RESULTS We observed a rise in erythrocyte glutathione by 27 % (P < 0.05), and a trend towards decreased plasma malondialdehyde in alpha-lipoic acid, but not in glutathione-treated animals in comparison with the placebo group. Simultaneously, sciatic nerve blood flow and vascular resistance were improved by daily alpha-lipoic acid administration by 38% (P < 0.05). Peripheral nerve conduction velocity and endoneurial glutathione were not significantly influenced by antioxidant treatment. CONCLUSIONS Only minor beneficial effects of alpha-lipoic acid on nerve blood flow and oxidative state occur at the given doses; these effects were insufficient to improve nerve conduction deficits.
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Affiliation(s)
- P S van Dam
- University Medical Center, Utrecht, The Netherlands.
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Sharma AK, Ponery AS, Lawrence PA, Ahmed I, Bastaki SM, Dhanasekaran S, Sheen RS, Adeghate E. Effect of alpha-tocopherol supplementation on the ultrastructural abnormalities of peripheral nerves in experimental diabetes. J Peripher Nerv Syst 2001; 6:33-9. [PMID: 11293806 DOI: 10.1046/j.1529-8027.2001.006001033.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ultrastructural observations were made on myelinated fibers in the tibial nerves in order to investigate the beneficial effects of alpha-tocopherol administration in streptozotocin-diabetic rats. Male Wistar rats, aged 12 weeks and weighing between 250 g to 300 g were studied. Six onset control rats were used to obtain the baseline parameters for this strain and age. Further 3 groups--untreated diabetic animals, diabetic animals treated with alpha-tocopherol, and age-matched controls--were studied over a 3-month period. In the diabetic animal, administration of alpha-tocopherol resulted in a significant increase (p < 0.05) in total plasma vitamin E levels when compared with other groups. Myelinated fiber cross-sectional area (p < 0.05), axonal area (p < 0.01) and myelin sheath area (p < 0.05) were significantly less in the tibial nerve of diabetic animals than in age-matched controls, but not different from those of onset controls. In the alpha-tocopherol treated diabetic animals, the values for these parameters were intermediate without showing significant difference when compared with age-matched controls and untreated diabetics. The "g" ratio (axon to fiber area) did not differ between any experimental groups. The number of large myelinated fibers were less in the untreated diabetic animals, but in the alpha-tocopherol-treated diabetics, the values were significantly higher (p < 0.05) than with untreated diabetics and were similar to those of age-matched controls. In conclusion, this ultrastructural study reiterated the fact that structural abnormalities of myelinated fibers occur in experimental diabetes and that alpha-tocopherol administration may be useful in preventing the development of these abnormalities.
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Affiliation(s)
- A K Sharma
- Department of Anatomy, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain.
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Abstract
Reactive oxygen species (ROS) are elevated by metabolic changes in diabetes, including autoxidation and increased advanced glycation. Endogenous protection by the glutathione redox cycle is also compromised by the competing NADPH requirement of elevated polyol pathway flux. Antioxidant treatment strategies prevent or reverse nerve conduction velocity (NCV) deficits in diabetic rats. These include lipophilic scavengers such as butylated hydroxytoluene, probucol and vitamin E, more hydrophilic agents like alpha-lipoic acid and acetyl cysteine, and transition metal chelators that inhibit autoxidation. In the long-term, elevated ROS cause cumulative damage to neurons and Schwann cells, however, they also have a deleterious effect on nerve blood flow in the short term. This causes endoneurial hypoxia, which is responsible for early NCV deficits. Antioxidant treatment corrects the blood flow deficit and promotes normal endoneurial oxygenation. ROS cause antioxidant-preventable vascular endothelium abnormalities, neutralizing nitric oxide mediated vasodilation and increasing reactivity to vasoconstrictors. Unsaturated fatty acids are a major target for ROS and essential fatty acid metabolism is impaired by diabetes. Gamma-linolenic acid stimulates vasodilator prostanoid production, and there are marked synergistic interactions between gamma-linolenic acid and antioxidants. This has encouraged the development of novel drugs such as ascorbyl-gamma-linolenic acid and gamma-linolenic acid-lipoic acid with enhanced therapeutic potential.
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Affiliation(s)
- N E Cameron
- Department of Biomedical Sciences, University of Aberdeen, Scotland, UK.
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van Dam PS, Bravenboer B, van Asbeck BS, Marx JJ, Gispen WH. High rat food vitamin E content improves nerve function in streptozotocin-diabetic rats. Eur J Pharmacol 1999; 376:217-22. [PMID: 10448879 DOI: 10.1016/s0014-2999(99)00376-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Antioxidants can improve nerve dysfunction in hyperglycaemic rats. We evaluated whether the standard supplementation of rat food with vitamin E (normally added for preservation purposes) or high-dose vitamin E treatment improves nerve conduction in maturing streptozotocin-diabetic rats, a model widely used to study diabetic neuropathy. Hyperglycaemic rats received food containing 25 mg/kg (non-supplemented), 70 mg/kg (standard food) or 12 g/kg (high-dose) vitamin E. Non-diabetic controls received non-supplemented food. Sciatic and tibial sensory and motor nerve conduction velocity were decreased in all diabetic animals. In comparison with standard feeding, the non-supplemented diabetic rats showed lower plasma vitamin E levels but no significant change in nerve conduction. High-dose treatment prevented nerve dysfunction by 50%, and led to attenuated endoneurial lipid peroxidation (measured as malondialdehyde). We conclude that high doses of vitamin E, but not standard vitamin E supplementation of rat food partially prevent nerve dysfunction in young adult streptozotocin-diabetic rats.
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Affiliation(s)
- P S van Dam
- Department of Medical Pharmacology, Rudolf Magnus Institute for Neurosciences, University Medical Center, Utrecht, The Netherlands.
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