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André-Lévigne D, Pignel R, Boet S, Jaquet V, Kalbermatten DF, Madduri S. Role of Oxygen and Its Radicals in Peripheral Nerve Regeneration: From Hypoxia to Physoxia to Hyperoxia. Int J Mol Sci 2024; 25:2030. [PMID: 38396709 PMCID: PMC10888612 DOI: 10.3390/ijms25042030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Oxygen is compulsory for mitochondrial function and energy supply, but it has numerous more nuanced roles. The different roles of oxygen in peripheral nerve regeneration range from energy supply, inflammation, phagocytosis, and oxidative cell destruction in the context of reperfusion injury to crucial redox signaling cascades that are necessary for effective axonal outgrowth. A fine balance between reactive oxygen species production and antioxidant activity draws the line between physiological and pathological nerve regeneration. There is compelling evidence that redox signaling mediated by the Nox family of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases plays an important role in peripheral nerve regeneration. Further research is needed to better characterize the role of Nox in physiological and pathological circumstances, but the available data suggest that the modulation of Nox activity fosters great therapeutic potential. One of the promising approaches to enhance nerve regeneration by modulating the redox environment is hyperbaric oxygen therapy. In this review, we highlight the influence of various oxygenation states, i.e., hypoxia, physoxia, and hyperoxia, on peripheral nerve repair and regeneration. We summarize the currently available data and knowledge on the effectiveness of using hyperbaric oxygen therapy to treat nerve injuries and discuss future directions.
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Affiliation(s)
- Dominik André-Lévigne
- Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, 1205 Geneva, Switzerland
| | - Rodrigue Pignel
- Subaquatic and Hyperbaric Medicine Unit, Division of Emergency Medicine, Department of Anesthesiology, Clinical Pharmacology, Intensive Care and Emergency Medicine, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
| | - Sylvain Boet
- Subaquatic and Hyperbaric Medicine Unit, Division of Emergency Medicine, Department of Anesthesiology, Clinical Pharmacology, Intensive Care and Emergency Medicine, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
- Department of Anesthesiology and Pain Medicine, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada
- Ottawa Hospital Research Institute, Clinical Epidemiology Program, Department of Innovation in Medical Education, University of Ottawa, Ottawa, ON K1H 8L6, Canada
- Institut du Savoir Montfort, Ottawa, ON K1K 0T2, Canada
| | - Vincent Jaquet
- Department of Cell Physiology and Metabolism, University of Geneva, 1205 Geneva, Switzerland
- READS Unit, Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
| | - Daniel F. Kalbermatten
- Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, 1205 Geneva, Switzerland
- Bioengineering and Neuroregeneration Laboratory, Department of Surgery, University of Geneva, 1205 Geneva, Switzerland
| | - Srinivas Madduri
- Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, 1205 Geneva, Switzerland
- Bioengineering and Neuroregeneration Laboratory, Department of Surgery, University of Geneva, 1205 Geneva, Switzerland
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Ischemia-Reperfusion Injury of Sciatic Nerve in Rats: Protective Role of Combination of Vitamin C with E and Tissue Plasminogen Activator. Neurochem Res 2018; 43:650-658. [PMID: 29327309 DOI: 10.1007/s11064-017-2465-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/23/2017] [Accepted: 12/30/2017] [Indexed: 10/18/2022]
Abstract
An ischemia/reperfusion injury of rat's sciatic nerve was experimentally developed. In this model, we measured the in vivo production of superoxide radical, as a marker of oxidative stress and the occludin expression as an indicator of blood-nerve barrier function and we examined potential protective innervations against these abnormalities. Right sciatic nerves of the animals underwent 3 h of ischemia followed by 7 days of reperfusion and were divided into three groups: ischemic, pretreated with vitamin C in conjunction with vitamin E and treated with tissue plasminogen activator. Compared to measurements from left sciatic nerves used as sham, the ischemic group showed significantly increased superoxide radical and reduced expression of occludin in western blot and immunohistochemistry. No such differences were detected between sham and nerves in the vitamin or tissue plasminogen activator groups. It is suggested that the experimental ischemia/reperfusion model was suitable for studying the relationship between oxidative state and blood-nerve barrier. The reversion of abnormalities by the applied neuroprotective agents might prove to be a clinically important finding in view of the implication of vascular supply derangement in various neuropathies in humans.
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Alipour M, Mohsen A, Gadiri-Soufi F, Farhad GS, Jafari MR, Mohammad-Reza J. Effect of aminoguanidine on sciatic functional index, oxidative stress, and rate of apoptosis in an experimental rat model of ischemia-reperfusion injury. Can J Physiol Pharmacol 2014; 92:1013-9. [PMID: 25391296 DOI: 10.1139/cjpp-2014-0315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was conducted to investigate the potential protective effects of aminoguanidine (AG) on sciatic functional index (SFI), oxidative stress status, and apoptosis index using a rat model of experimental sciatic nerve ischemia-reperfusion injury (I/R). Treatment groups received 150 mg AG/kg body mass, 24 h after the induction of ischemia. After reperfusion for 2, 4, 7, 14, and 28 days, we evaluated measured SFI, plasma antioxidant enzymes, total antioxidant capacity (TAC), malondialdehyde (MDA), and index of apoptosis. SFI was significantly improved on the 7th and 14th day of reperfusion in the AG-treated groups. AG treatment resulted in the significant reduction of MDA levels on the 7th and 14th day of reperfusion. TAC was only increased after 7 days of reperfusion compared with the untreated group. SOD activity was decreased in both the untreated and AG-treated groups by comparison with the control, but did not show a significant change. GPx activity decreased only after 7 days of reperfusion. The maximal rate of apoptosis occurred on the 7th day of reperfusion. Treatment with AG significantly reduced this enhancement. AG exhibits positive effects against sciatic nerve I/R injury, possibly in part because of the protective effects of AG against apoptosis and I/R-induced oxidative stress.
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Affiliation(s)
| | - Alipour Mohsen
- a Department of Physiology & Pharmacology, School of Medicine, Kramandan, Zanjan University of Medical Sciences, 4513956111, Islamic Republic of Iran
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Calcium Channel Blockers Reduce the Effects of Cigarette Smoking on Peripheral Nerve Ischemia/Reperfusion Injury. Ann Plast Surg 2013; 70:222-6. [DOI: 10.1097/sap.0b013e3182367be1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Intraperitoneal Aminoguanidine Improves Sciatic Nerve Ischemia–Reperfusion Injury in Male Sprague-Dawley Rats. Cell Mol Neurobiol 2011; 31:765-73. [DOI: 10.1007/s10571-011-9682-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 02/23/2011] [Indexed: 01/08/2023]
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Increased susceptibility to ischemia and macrophage activation in STZ-diabetic rat nerve. Brain Res 2010; 1373:172-82. [PMID: 21134361 DOI: 10.1016/j.brainres.2010.11.084] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/22/2010] [Accepted: 11/25/2010] [Indexed: 01/04/2023]
Abstract
Ischemic vulnerability in diabetic nerve plays a paramount role in the development of diabetic neuropathy, yet little is known of the underlying mechanism. Diabetes enhances the inflammatory response to ischemia and reperfusion. We investigated pathological characteristics of nerve fibers and endoneurial macrophages along the length of sciatic-tibial nerves before and after ischemia (60 to 90 min) and reperfusion (6h to 7 days) in 8 weeks of STZ-induced diabetic rats. Without ischemia, diabetic nerves revealed significantly increased the density of Iba-1-positive endoneurial macrophages when compared with controls. Most of macrophages appeared slim and triangular in shape, but in diabetic nerves, some were rounded with bromodeoxyuridine (BrdU) incorporation, suggesting proliferating macrophages. Seventy-five minutes of ischemia is the minimal ischemic time to cause pathological changes in diabetic nerves. Following 90 min of ischemia and 6h of reperfusion in diabetic rats, the number of Iba-1-positive endoneurial macrophages was increased significantly at the thigh level of sciatic nerve when compared with those before ischemia. Endoneurial macrophages in diabetic nerves increased in number further significantly after 24 and 48 h of reperfusion and underwent morphological alterations; swollen and rounded including phagocytosis. After 90 min of ischemia and 7 days of reperfusion, severe pathological alterations, e.g., demyelination and endoneurial edema at proximal nerves and axonal degeneration distally, were observed in diabetic nerves, while control nerves showed normal morphology. We conclude that macrophage proliferation occurs in STZ-diabetic nerves. The acute inflammatory response after ischemia and reperfusion was intensified in diabetic nerves. Activation of resident macrophages and infiltration by recruited macrophages could be casually linked to ischemic susceptibility in diabetic nerve.
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Gholami MR, Abolhassani F, Pasbakhsh P, Akbari M, Sobhani A, Eshraghian MR, Kamalian N, Amoli FA, Dehpoor AR, Sohrabi D. The effects of simvastatin on ischemia–reperfusion injury of sciatic nerve in adult rats. Eur J Pharmacol 2008; 590:111-4. [DOI: 10.1016/j.ejphar.2008.05.050] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 04/20/2008] [Accepted: 05/20/2008] [Indexed: 10/22/2022]
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Wang Y, Schmelzer JD, Schmeichel A, Iida H, Low PA. Ischemia–reperfusion injury of peripheral nerve in experimental diabetic neuropathy. J Neurol Sci 2004; 227:101-7. [PMID: 15546599 DOI: 10.1016/j.jns.2004.09.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The pathogenesis of human diabetic neuropathy likely involves the interplay of hyperglycemia, ischemia, and oxidative stress. Mild-moderate ischemia-reperfusion to streptozotocin (STZ)-induced diabetes results in florid fiber degeneration in diabetic but not in normal nerves. Uncertainty exists as to the influence of duration of diabetes on this susceptibility. We therefore studied diabetic tibial and sciatic nerves using a rat ischemia-reperfusion (IR) model after 1 month and 4 months of diabetes utilizing electrophysiological, behavioral, and neuropathological methods. Electrophysiological abnormalities were present in 1-month diabetic rats (D) and persisted over 4 months. Behavioral scores were decreased markedly at 4 months (p<0.05). Endoneurial edema and ischemia fiber degeneration (IFD) were observed at both the 1-month (p<0.01 and p<0.001) and 4-month (p<0.001) durations in diabetic nerves, whereas only mild or no damage was observed in age-matched control nerves. These findings demonstrate that STZ-induced diabetes exacerbates the morphological and electrophysiological pathology in peripheral nerve to IR injury both in the early timepoint of 1 month and late timepoint of 4 months, although there was a gradation of injury, which is more severe at the later timepoint. Reperfusion exaggerated morphological pathology in 1-month STZ-induced diabetic peripheral nerve.
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Affiliation(s)
- Yanping Wang
- Department of Neurology, Mayo Clinic, 811 Guggenheim, 200 First Street SW, Rochester, MN 55905, USA
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Iida H, Schmelzer JD, Schmeichel AM, Wang Y, Low PA. Peripheral nerve ischemia: reperfusion injury and fiber regeneration. Exp Neurol 2003; 184:997-1002. [PMID: 14769393 DOI: 10.1016/s0014-4886(03)00385-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Revised: 07/10/2003] [Accepted: 07/23/2003] [Indexed: 11/15/2022]
Abstract
We continued our studies of ischemia-reperfusion (IR) injury, extending the reperfusion duration to 42 days to capture the fiber regeneration process. We used a rat model for IR injury produced by ligation and release of nooses around supplying vessels to the sciatic nerve. Fifty-six rats were used. One group (control N = 8) underwent sham ischemia; the other six groups (N = 8 each) underwent complete hind limb ischemia for 4 h followed by reperfusion durations of 0 h (ischemia alone), 3 h, 7 days, 14 days, 28 days, and 42 days. Behavioral and electrophysiological data were obtained immediately before euthanasia. Pathologically, three phases were identifiable: Phase 1 (0-3 h)-minimal pathological changes, minimal edema; phase 2 (7 days, 14 days)-prominent fiber degeneration, endoneurial edema; phase 3 (28 days, 42 days)-abundant small regenerating fiber clusters, minimal edema. Compound muscle action potential (CMAP) was the most sensitive index of neural deficits and recovery, showing progressive recovery beyond 14 days. Severe functional deficits developed immediately and persisted with a trend to recovery at the 42-day time-point. It was concluded that reperfusion, by oxidative injury, worsened nerve function and aggravated fiber degeneration, but in the longer time frame, permitted fiber regeneration to occur.
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Affiliation(s)
- Haruyasu Iida
- Mayo Clinic, Department of Neurology, Rochester, MN 55905, USA
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Gray C, Nukada H, Jackson DM, McMorran PD, Wu A, Ma F. Neuroprotective effects of nitrone radical scavenger S-PBN on reperfusion nerve injury in rats. Brain Res 2003; 982:179-85. [PMID: 12915253 DOI: 10.1016/s0006-8993(03)03006-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The nitrone-based free radical scavengers have potent neuroprotective activities in models of stroke in which oxidative stress plays a key role in its development. We examined the effects of S-PBN (sodium 4-[(tert-butylimino) methyl]benzene-3-sulfonate N-oxide), a spin trap nitrone, on reperfusion injury in rat peripheral nerves. Immediately after the onset of 4-h ischaemia in rat right hindlimb, S-PBN was administered via mini-osmotic pumps, containing 2 ml of S-PBN (1.2 M), inserted subcutaneously. S-PBN, in addition, was given by a single injection (50 mg/kg BW, i.p.). Mean plasma concentrations of S-PBN were significantly greater in S-PBN-treated rats than in controls after 24, 48 and 72 h of reperfusion. Pump and dosing solution analysis indicated that the rats received between 82 and 99% of the target S-PBN concentration. Morphology in sciatic, tibial and peroneal nerves was assessed after 4 h of ischaemia followed by 72 h and 7 days of reperfusion. After 72 h of reperfusion, saline-treated control rats showed endoneurial oedema at the thigh level and diffuse axonal degeneration of myelinated nerve fibres distally. S-PBN-treated nerves were normal or revealed less severe abnormalities in myelinated fibres after 72 h and 7 days of reperfusion, when compared with those in saline-treated control nerves. Morphometrically, the frequency of abnormal myelinated fibres at calf levels was significantly less in S-PBN-treated nerves than in controls. In conclusion, post-ischaemic administration of S-PBN exhibits substantial neuroprotective properties in ischemia/reperfusion nerve injury.
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Affiliation(s)
- Chris Gray
- Department of Pharmacology and Toxicology, University of Otago Medical School, Dunedin 9015, New Zealand
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Ohshima J, Nukada H. Hypoglycaemic neuropathy: microvascular changes due to recurrent hypoglycaemic episodes in rat sciatic nerve. Brain Res 2002; 947:84-9. [PMID: 12144856 DOI: 10.1016/s0006-8993(02)02910-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Intensive diabetes treatment causes a considerable increase in the number of severe hypoglycaemic episodes which could aggravate the progression of diabetic neuropathy. However, the effect of repeated hypoglycaemic episodes on nerve morphology has never been previously investigated. The aims of the present study were: (i) to establish a rat model of recurrent episodes of severe hypoglycaemia, and (ii) to assess morphological changes after repeated hypoglycaemic episodes in rat sciatic nerves. We induced hypoglycaemic episodes, blood glucose level <3.0 mmol/l for 3 h, by injecting regular insulin intravenously on 4 consecutive days. We found endothelial swelling of endoneurial microvessels at the thigh level of sciatic and tibial nerves 24 h after four daily episodes of hypoglycaemia. Endothelial swelling was confirmed by vascular morphometry which showed significantly increased endothelial and pericyte areas. No obvious abnormalities were seen on nerve fibres. In conclusion, recurrent hypoglycaemic episodes cause early vascular anomalies in endoneurial microvessels in rat sciatic nerves without any observable changes in nerve fibres.
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Affiliation(s)
- Jun Ohshima
- Department of Medicine, University of Otago Medical School, Dunedin, New Zealand
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Abstract
The streptozocin (STZ)-diabetic nerve manifests increased morphological susceptibility to a superimposed acute ischemic injury, and reperfusion injury exaggerates ischemic nerve pathology. To determine whether STZ-diabetic nerves are susceptible to reperfusion, we evaluated the pathological consequences after 2.5 hours of ischemia followed by 3 and 24 hours of reperfusion in a 20-week STZ-diabetic rat sciatic nerve. After 3 hours of reperfusion, endoneurial edema developed in diabetic nerves, whereas non-diabetic controls showed mild or no edema. Morphometric analysis of endoneurial edema, quantified by the total transverse fascicular area and the point-count score of endoneurial structureless space, confirmed significantly more reperfusion-induced edema at thigh and knee levels in diabetic nerves than in controls. Reperfusion caused a significant increase in the number of endoneurial mast cells at the thigh level in diabetic nerves. After 24 hours of reperfusion, there were striking morphological anomalies of myelinated nerve fibers in diabetic nerves, without any observable changes in control nerves. In conclusion, we have demonstrated that STZ-diabetes exacerbates the morphological change to reperfusion. Diabetes therefore renders the microvasculature more vulnerable to the deleterious effects of ischemia/reperfusion.
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Affiliation(s)
- Hitoshi Nukada
- Department of Medicine, University of Otago Medical School, Dunedin, New Zealand.
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He K, Nukada H, McMorran PD, Murphy MP. Protein carbonyl formation and tyrosine nitration as markers of oxidative damage during ischaemia-reperfusion injury to rat sciatic nerve. Neuroscience 1999; 94:909-16. [PMID: 10579583 DOI: 10.1016/s0306-4522(99)00350-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have investigated the role of oxidative damage in peripheral nerve ischaemia-reperfusion injury using a rat sciatic nerve model. After 5 h ischaemia blood flow to the sciatic nerve was restarted and markers of oxidative damage measured after various times of reperfusion. As a marker of protein oxidative damage, protein carbonyl formation was measured using a sensitive enzyme-linked immunosorbent assay. Protein carbonyl content was unaffected by ischaemia alone, but increased by 55% after 12-18 h reperfusion, correlating with the onset of nerve pathology. Pretreatment with the xanthine oxidase inhibitor allopurinol prevented these abnormalities, suggesting that xanthine oxidase activity is proximal to oxidative damage during reperfusion injury. To determine whether formation of the potent oxidant peroxynitrite from nitric oxide and superoxide contributed to ischaemia-reperfusion injury, we measured the accumulation of 3-nitrotyrosine residues in proteins. Only one protein of 49,000 mol. wt contained significant amounts of 3-nitrotyrosine residues which was shown to be glial fibrillary acidic protein, an abundant cytoskeletal protein in Schwann cells. However glial fibrillary acidic protein contained 3-nitrotyrosine residues prior to ischaemia-reperfusion, and the amount of nitrated tyrosine residues in total glial fibrillary acidic protein did not increase significantly during reperfusion, therefore it was not possible to draw conclusions about the role of peroxynitrite in nerve reperfusion injury.
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Affiliation(s)
- K He
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Mitsui Y, Schmelzer JD, Zollman PJ, Mitsui M, Kihara M, Low PA. Hypothermic neuroprotection of peripheral nerve of rats from ischemia-reperfusion injury: intraischemic vs. reperfusion hypothermia. Brain Res 1999; 827:63-9. [PMID: 10320694 DOI: 10.1016/s0006-8993(99)01289-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The pathophysiology of ischemic fiber degeneration (IFD) is not known, but mechanisms involved during nerve ischemia differ from those during reperfusion. We have previously demonstrated hypothermic neuroprotection of peripheral nerve from IFD. We now evaluate the efficacy of hypothermia in the intraischemic vs. the reperfusion period, using our established model of ischemia-reperfusion injury. Intraischemic hypothermia resulted in significant recovery of all indices (behavior score, electrophysiology and histology, P<0.01 or 0.05) while hypothermia during reperfusion period showed less improvement, significant only for the histological score compared to normothermia group (IFD index, P<0.05). Once hypothermia was applied in the ischemic period, the resultant neuroprotection continued into the reperfusion period, even if nerve temperature was then raised during the reperfusion period. These results indicate that hypothermic neuroprotection is more efficacious during the intraischemic period than during reperfusion, when a lesser degree of neuroprotection ensued.
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Affiliation(s)
- Y Mitsui
- Department of Neurology, Mayo Clinic, 811 Guggenheim Building, 200 First Street SW, Rochester, MN 55905, USA
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Mitsui Y, Schmelzer JD, Zollman PJ, Mitsui M, Tritschler HJ, Low PA. Alpha-lipoic acid provides neuroprotection from ischemia-reperfusion injury of peripheral nerve. J Neurol Sci 1999; 163:11-6. [PMID: 10223404 DOI: 10.1016/s0022-510x(99)00017-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Reperfusion aggravates nerve ischemic fiber degeneration, likely by the generation of reduced oxygen species. We therefore evaluated if racemic alpha-lipoic acid (LA), a potent antioxidant, will protect peripheral nerve from reperfusion injury, using our established model of ischemia-reperfusion injury. METHODS We used male SD rats, 300+/-5 g. Ischemia was produced by the ligature of each of the supplying arteries to the sciatic-tibial nerve of the right hind-limb for predetermined periods of time (either 3 or 5 h), followed by the release of the ligatures, resulting in reperfusion. LA was given intraperitoneally daily for 3 days for both pre- and post-surgery. Animals received either LA, 100 mg/kg/day, or the same volume of saline intraperitoneally. Clinical behavioral score and electrophysiology of motor and sensory nerves were obtained at 1 week after ischemia-reperfusion. After electrophysiological examination, the sciatic-tibial nerve was fixed in situ and embedded in epon. We evaluated for ischemic fiber degeneration (IFD) and edema, as we described previously. RESULTS Distal sensory conduction (amplitude of sensory action potential and sensory conduction velocity (SCV) of digital nerve) was significantly improved in the 3-h ischemia group, treated with LA (P<0.05). LA also improved IFD of the mid tibial nerve (P=0.0522). LA failed to show favorable effects if the duration of ischemia was longer (5-h ischemia). CONCLUSION These results suggest that alpha-lipoic acid is efficacious for moderate ischemia-reperfusion, especially on distal sensory nerves.
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Affiliation(s)
- Y Mitsui
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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McKenzie D, Nukada H, van Rij AM, McMorran PD. Endoneurial microvascular abnormalities of sural nerve in non-diabetic chronic atherosclerotic occlusive disease. J Neurol Sci 1999; 162:84-8. [PMID: 10064174 DOI: 10.1016/s0022-510x(98)00303-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neuropathic abnormalities are found in chronically ischaemic limbs associated with non-diabetic atherosclerotic peripheral vascular disease (PVD). In chronic ischaemic neuropathy, microvascular alterations play a key role in its development. We undertook morphometric assessment of endoneurial microvessels in the sural nerves, taken from severely ischaemic amputated legs in nine chronic non-diabetic PVD. These subjects had threatened ischaemic limbs and revealed clinical, physiological and pathological evidence of neuropathy. For comparison, sural nerves taken from amputated legs due to non-ischaemic disorders (n=4) and chronic PVD associated with diabetes (n=3) were also assessed. We evaluated the areas of vascular lumen, endothelial cells and whole vessel, as well as the percentage of closed capillaries. Endothelial area of sural nerve microvessels in non-diabetic PVD nerves was significantly greater than in non-ischaemic control nerves. Periendothelial cell area containing pericytes and basement membranes was also significantly increased in non-diabetic PVD nerves when compared with control nerves. Vascular lumen area was significantly less in non-diabetic PVD nerves than in non-ischaemic control nerves. Endoneurial microvessels in diabetic PVD nerves showed similar results: thickened vessel wall and smaller lumen. Periendothelial area in diabetic nerves was significantly greater than in non-diabetic PVD nerves. We demonstrated swollen endothelial cells and increased periendothelial area associated with narrowed lumen in sural nerve endoneurial microvessels of severe chronic PVD. Basement membrane reduplication of endoneurial capillaries was seen in non-diabetic PVD nerves. These microvascular abnormalities could play an important role in the development of chronic ischaemic neuropathy in PVD limbs.
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Affiliation(s)
- D McKenzie
- Department of Medicine, University of Otago Medical School, Dunedin, New Zealand
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