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Sharma KK, Fatima N, Ali Z, Moshin M, Chandra P, Verma A, Goshain O, Kumar G. Neuropathy, its Profile and Experimental Nerve Injury Neuropathic Pain Models: A Review. Curr Pharm Des 2023; 29:3343-3356. [PMID: 38058089 DOI: 10.2174/0113816128274200231128065425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/17/2023] [Accepted: 11/06/2023] [Indexed: 12/08/2023]
Abstract
Neuropathy is a terrible disorder that has a wide range of etiologies. Drug-induced neuropathy, which happens whenever a chemical agent damages the peripheral nerve system, has been linked here to the iatrogenic creation of some drugs. It is potentially permanent and causes sensory impairments and paresthesia that typically affects the hands, feet, and stockings; motor participation is uncommon. It might appear suddenly or over time, and the long-term outlook varies. The wide range of chronic pain conditions experienced by people has been one of the main obstacles to developing new, more effective medications for the treatment of neuropathic pain. Animal models can be used to examine various neuropathic pain etiologies and symptoms. Several models investigate the peripheral processes of neuropathic pain, whereas some even investigate the central mechanisms, such as drug induce models like vincristine, cisplatin, bortezomib, or thalidomide, etc., and surgical models like sciatic nerve chronic constriction injury (CCI), sciatic nerve ligation through spinal nerve ligation (SNL), sciatic nerve damage caused by a laser, SNI (spared nerve injury), etc. The more popular animal models relying on peripheral nerve ligatures are explained. In contrast to chronic sciatic nerve contraction, which results in behavioral symptoms of less reliable stressful neuropathies, (SNI) spared nerve injury generates behavioral irregularities that are more feasible over a longer period. This review summarizes the latest methods models as well as clinical ideas concerning this mechanism. Every strongest current information on neuropathy is discussed, along with several popular laboratory models for causing neuropathy.
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Affiliation(s)
- Krishana Kumar Sharma
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Nishat Fatima
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Zeeshan Ali
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Mohd Moshin
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Phool Chandra
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Anurag Verma
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Omprakash Goshain
- Department of Pharmacology, Teerthanker Mahaveer College of Pharmacy, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh 244001, India
| | - Gajendra Kumar
- Department of Chemistry, Constituent Government College (M.J.P.R.U.), Hasanpur, Uttar Pradesh 244241, India
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Nieto FR, Cendán CM, Cañizares FJ, Cubero MA, Vela JM, Fernández-Segura E, Baeyens JM. Genetic inactivation and pharmacological blockade of sigma-1 receptors prevent paclitaxel-induced sensory-nerve mitochondrial abnormalities and neuropathic pain in mice. Mol Pain 2014; 10:11. [PMID: 24517272 PMCID: PMC3924235 DOI: 10.1186/1744-8069-10-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 02/07/2014] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Paclitaxel, a widely-used antineoplastic drug, produces a painful peripheral neuropathy that in rodents is associated with peripheral-nerve mitochondrial alterations. The sigma-1 receptor (σ1R) is a ligand-regulated molecular chaperone involved in mitochondrial calcium homeostasis and pain hypersensitivity. This receptor plays a key role in paclitaxel-induced neuropathic pain, but it is not known whether it also modulates mitochondrial abnormalities.In this study, we used a mouse model of paclitaxel-induced neuropathic pain to test the involvement of the σ1R in the mitochondrial abnormalities associated with paclitaxel, by using genetic (σ1R knockout mice) and pharmacological (σ1R antagonist) approaches. RESULTS Paclitaxel administration to wild-type (WT) mice produced cold- and mechanical-allodynia, and an increase in the frequency of swollen and vacuolated mitochondria in myelinated A-fibers, but not in C-fibers, of the saphenous nerve. Behavioral and mitochondrial alterations were marked at 10 days after paclitaxel-administration and had resolved at day 28. In contrast, paclitaxel treatment did not induce allodynia or mitochondrial abnormalities in σ1R knockout mice. Moreover, the prophylactic treatment of WT mice with BD-1063 also prevented the neuropathic pain and mitochondrial abnormalities induced by paclitaxel. CONCLUSIONS These results suggest that activation of the σ1R is necessary for development of the sensory nerve mitochondrial damage and neuropathic pain produced by paclitaxel. Therefore, σ1R antagonists might have therapeutic value for the prevention of paclitaxel-induced neuropathy.
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Affiliation(s)
- Francisco R Nieto
- Department of Pharmacology, Biomedical Research Centre and Institute of Neuroscience, University of Granada, 18012 Granada, Spain
- Current address: Wolfson Centre for Age-Related Diseases, King’s College London, Wolfson Wing, Hodgkin Building, SE1 1UL London, UK
| | - Cruz M Cendán
- Department of Pharmacology, Biomedical Research Centre and Institute of Neuroscience, University of Granada, 18012 Granada, Spain
| | - Francisco J Cañizares
- Department of Histology, Biomedical Research Centre and Institute of Neuroscience, University of Granada, 18012 Granada, Spain
| | - María A Cubero
- Department of Histology, Biomedical Research Centre and Institute of Neuroscience, University of Granada, 18012 Granada, Spain
| | - José M Vela
- Esteve, Drug Discovery and Preclinical Development, Parc Científic de Barcelona, Carrer Baldiri Reixac, 4-8, 08028 Barcelona, Spain
| | - Eduardo Fernández-Segura
- Department of Histology, Biomedical Research Centre and Institute of Neuroscience, University of Granada, 18012 Granada, Spain
| | - José M Baeyens
- Department of Pharmacology, Biomedical Research Centre and Institute of Neuroscience, University of Granada, 18012 Granada, Spain
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Toledo-Corral CM, Banner LR. Early changes of LIFR and gp130 in sciatic nerve and muscle of diabetic mice. Acta Histochem 2012; 114:159-65. [PMID: 21565387 DOI: 10.1016/j.acthis.2011.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 04/11/2011] [Accepted: 04/12/2011] [Indexed: 11/15/2022]
Abstract
Peripheral neuropathy is a common complication of diabetes mediated by alterations of growth factors. Members of the neuropoietic cytokine family, which include IL-6, LIF, and CNTF among others, have been shown to be important regulators of peripheral nerves and the muscles that they innervate. To investigate their potential role in diabetic nerve and muscle, we studied the expression of the shared receptor subunits, LIFR and gp130 in a mouse model of streptozotocin (STZ)-induced diabetes. The results of Western blotting and densitometric analysis showed that both LIFR and gp130 protein expression were increased in diabetic sciatic nerve compared to control mice at early time points following STZ injection. In diabetic gastrocnemius muscle, LIFR and gp130 were increased from 3 days to 24 weeks following STZ injection. In contrast, both LIFR and gp130 protein expression were decreased in diabetic soleus muscle at 3-days post-injection. Our results suggest that hyperglycemia results in changes to nerve and muscle soon after the onset of diabetes and that cytokines may play a role in this process.
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Argyriou AA, Koltzenburg M, Polychronopoulos P, Papapetropoulos S, Kalofonos HP. Peripheral nerve damage associated with administration of taxanes in patients with cancer. Crit Rev Oncol Hematol 2008; 66:218-28. [PMID: 18329278 DOI: 10.1016/j.critrevonc.2008.01.008] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 01/15/2008] [Accepted: 01/25/2008] [Indexed: 11/17/2022] Open
Abstract
Peripheral neuropathy is a well recognized toxicity of taxanes, usually resulting to dose modification and changes in the treatment plan. Taxanes produce a symmetric, axonal predominantly sensory distal neuropathy with less prominent motor involvement. A "dying back" process starting from distal nerve endings followed by effects on Schwann cells, neuronal body or axonal transport changes and a disturbed cytoplasmatic flow in the affected neurons is the most widely accepted mechanism of taxanes neurotoxicity. The incidence of taxanes-induced peripheral neuropathy is related to causal factors, such as single dose per course and cumulative dose and risk factors including treatment schedule, prior or concomitant administration of platinum compounds or vinca alcaloids, age and pre-existing peripheral neuropathy of other causes. The most reliable method to assess taxanes neurotoxicity is by clinical examination combined with electrophysiological evaluation. There is currently no effective symptomatic treatment for paclitaxel-associated pain, myalgias and arthralgias. Tricyclic antidepressants and anticonvulsants have been used as symptomatic treatment of neurotoxicity with some measure of success. Therefore, new approaches for prophylaxis against taxanes-induced peripheral neuropathy are needed. Several neuroprotective agents including, thiols, neurotrophic factors, and antioxidants hold promise for their ability to prevent neurotoxicity resulting from taxanes exposure. However, further confirmatory trials are warranted on this important clinical topic. This review critically looks at the pathogenesis, incidence, risk factors, diagnosis, characteristics and management of taxanes-induced peripheral neuropathy. We also highlight areas of future research.
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Affiliation(s)
- Andreas A Argyriou
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, UCL, Institute for Neurology, Queen Square, London WC1N3BG, UK.
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Bianchi R, Gilardini A, Rodriguez-Menendez V, Oggioni N, Canta A, Colombo T, De Michele G, Martone S, Sfacteria A, Piedemonte G, Grasso G, Beccaglia P, Ghezzi P, D'Incalci M, Lauria G, Cavaletti G. Cisplatin-induced peripheral neuropathy: Neuroprotection by erythropoietin without affecting tumour growth. Eur J Cancer 2007; 43:710-7. [PMID: 17251006 DOI: 10.1016/j.ejca.2006.09.028] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 09/11/2006] [Accepted: 09/19/2006] [Indexed: 11/27/2022]
Abstract
This study examined the dose-dependent efficacy of erythropoietin (EPO) for preventing and/or treating cisplatin (CDDP) induced peripheral neurotoxicity (CINP), and its influence on tumour treatment and growth. Rats received eight intraperitoneal (ip) injections of 2 mg/kg CDDP twice weekly. EPO co-administered (50 or 10 microg/kg ip, three times/week) had a dose-dependent effect, partially preventing CINP, but 0.5 microg/kg ip was not effective. The neuroprotective effect lasted at least 5 weeks after the last dose of EPO and CDDP. In addition, EPO (50 microg/kg ip three times/week) after the last injection of CDDP still induced a significant recovery of CINP. In a separate experiment in rats bearing mammary carcinoma EPO treatment (50 microg/kg ip) given concurrently with CDDP (1.0 and 1.5 mg/kg twice a week for four weeks) was neuroprotective without influencing the effectiveness of the treatment or tumour growth. EPO thus appears to be an effective neuroprotectant that does not interfere with tumour treatment.
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Affiliation(s)
- Roberto Bianchi
- Mario Negri Institute of Pharmacological Research, Milan, Italy
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Persohn E, Canta A, Schoepfer S, Traebert M, Mueller L, Gilardini A, Galbiati S, Nicolini G, Scuteri A, Lanzani F, Giussani G, Cavaletti G. Morphological and morphometric analysis of paclitaxel and docetaxel-induced peripheral neuropathy in rats. Eur J Cancer 2005; 41:1460-6. [PMID: 15913989 DOI: 10.1016/j.ejca.2005.04.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 03/29/2005] [Accepted: 04/01/2005] [Indexed: 11/17/2022]
Abstract
The experimentally induced neurotoxic effects of paclitaxel and docetaxel have never been compared, since no animal models of docetaxel peripheral neurotoxicity have yet been reported. In this experiment, we examined the effect of the chronic administration of these two taxanes in the Wistar rat using neurophysiological, neuropathological and morphometrical methods. Our results showed that both paclitaxel and docetaxel induced a significant, equally severe and dose-dependent reduction in nerve conduction velocity. On the contrary, the morphometric examination demonstrated that the effect on the nerve fibres was more severe after paclitaxel administration when the same schedule was used. However, the overall severity of the pathological changes was milder than expected on the basis of the neurophysiological results. Our results support the hypothesis that taxanes (and particularly docetaxel) may exert their neurotoxic effect not only on the microtubular system of the peripheral nerves, but also on other less obvious targets.
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Affiliation(s)
- Elke Persohn
- Novartis Pharma AG, Safety Profiling Assessment, Pathology, Basel, Switzerland
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Affiliation(s)
- Martin J van den Bent
- Neuro-oncology Unit, Daniel den Hoed Oncology Center/Erasmus University Medical Center, PO Box 5201, 3008 AE Rottterdam, Netherlands.
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Davis ID, Kiers L, MacGregor L, Quinn M, Arezzo J, Green M, Rosenthal M, Chia M, Michael M, Bartley P, Harrison L, Daly M. A randomized, double-blinded, placebo-controlled phase II trial of recombinant human leukemia inhibitory factor (rhuLIF, emfilermin, AM424) to prevent chemotherapy-induced peripheral neuropathy. Clin Cancer Res 2005; 11:1890-8. [PMID: 15756015 DOI: 10.1158/1078-0432.ccr-04-1655] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE To determine whether recombinant human leukemia inhibitory factor (rhuLIF, AM424, emfilermin) can prevent or ameliorate the development of chemotherapy-induced peripheral neuropathy (CIPN) after treatment with carboplatin (AUC 6) and paclitaxel (175 mg/m(2) over 3 hours). EXPERIMENTAL DESIGN Randomized double-blind placebo-controlled phase II clinical trial. Eligible patients had solid tumors for which treatment with carboplatin/paclitaxel was appropriate. The primary end point was a standardized composite peripheral nerve electrophysiology (CPNE) score, based on nerve velocities and amplitudes, measured at baseline and after four cycles of chemotherapy. Secondary efficacy end points included CPNE score at last cycle and at exit evaluation, vibration perception threshold, H-reflex latency, symptom scores, and quantitative assessment of neurologic signs. Study drug was given s.c. daily for 7 days starting the day before chemotherapy. Patients were randomized to receive low-dose rhuLIF (2 microg/kg), high-dose rhuLIF (4 microg/kg), or placebo. RESULTS Patients (n = 117) were randomized across seven neurology test centers. Thirty-six patients received low dose rhuLIF (2 microg/kg), 39 received high dose rhuLIF (4 microg/kg) and 42 received placebo. rhuLIF was well tolerated with 95% compliance and no adverse effects on quality of life. No differences between groups in CPNE or any of the individual neurologic testing variables were observed between baseline and cycle 4 or by the secondary efficacy variables. CONCLUSIONS rhuLIF is not effective in preventing CIPN caused by carboplatin and paclitaxel. CPNE is a reliable and valid tool that was sensitive to the onset and progression of CIPN.
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Affiliation(s)
- Ian D Davis
- Austin Health, Studley Road, Heidelberg, Victoria 3084, Australia.
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Flatters SJL, Bennett GJ. Ethosuximide reverses paclitaxel- and vincristine-induced painful peripheral neuropathy. Pain 2004; 109:150-61. [PMID: 15082137 DOI: 10.1016/j.pain.2004.01.029] [Citation(s) in RCA: 428] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Revised: 01/09/2004] [Accepted: 01/30/2004] [Indexed: 01/05/2023]
Abstract
Paclitaxel (Taxol) is one of the most effective and frequently used chemotherapeutics for the treatment of solid tumours. However, paclitaxel produces peripheral neurotoxicity with patients reporting sensory abnormalities and neuropathic pain during and often persisting after paclitaxel therapy. The mechanisms underlying this dose-limiting side effect are currently unknown and there are no validated drugs for its prevention or control. Male Sprague-Dawley rats received four intraperitoneal (i.p.) injections on alternate days of 2 mg/kg paclitaxel. Behavioural assessment using von Frey filaments and acetone showed that such paclitaxel treatment induced a pronounced mechanical and cold allodynia/hyperalgesia. Thus these studies aim to test potential analgesics on established paclitaxel-induced pain. Paclitaxel-induced pain appears to be relatively resistant to opioid therapy i.p. 4 mg/kg morphine was ineffective and i.p. 8 mg/kg morphine only elicited up to a 50% reversal of mechanical allodynia/hyperalgesia. Interestingly, a maximally tolerated dose (i.p. 0.2 mg/kg) of the potent NMDA receptor antagonist MK-801 produced no significant reversal of the mechanical allodynia/hyperalgesia suggesting that NMDA receptors have little role in paclitaxel-induced pain. Ethosuximide (i.p. 450 mg/kg) an anti-epileptic and relatively selective T-type calcium channel blocker elicited a near complete reversal of mechanical allodynia/hyperalgesia. Repetitive dosing with ethosuximide (i.p. 100 or 300 mg/kg daily for 3 days) showed a dose-related consistent reversal of mechanical allodynia/hyperalgesia with no evidence of tolerance. Ethosuximide (i.p. 300 mg/kg) also reversed paclitaxel-induced cold allodynia and vincristine-induced mechanical allodynia/hyperalgesia. These data suggest that T-type calcium channels may play a role in chemotherapy-induced neuropathy and moreover identify ethosuximide as a new potential treatment for chemotherapy-induced pain.
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Affiliation(s)
- Sarah J L Flatters
- Anaesthesia Research Unit, McIntyre Building, Room 1213, McGill University, 3655 Promenade Sir William Osler, Montreal, Qc, Canada H3G 1Y6.
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Abstract
Taxane anticancer agents play a central role in drug therapy for breast cancer today; however, they have a dose-limiting neurotoxicity that is difficult to prevent and treat. To protect against this neurotoxicity it is important to avoid large doses greater than 200 mg/m2, and to adopt 24-hour administration regimens. Care is also needed with regard to the cumulative dose. Glutamine and amitriptyline are two of the very few drugs that have been found to be clinically effective against drug-induced peripheral neuropathy. Drugs are discontinued if neuropathy appears. If administration is to be later restarted, it is recommended that combined use of glutamine or amitriptyline be considered and that patients be given guidance for daily life.
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Affiliation(s)
- Haruhiko Makino
- Department of Surgery, Niigata Prefectural Sakamachi Hospital, 589 Ooaza-Shimokajiya, Arakawamachi, Iwafune-gun, Niigata 959-3193, Japan
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Feeney SJ, Austin L, Bennett TM, Kurek JB, Jean-Francois MJB, Muldoon C, Byrne E. The effect of leukaemia inhibitory factor on SOD1 G93A murine amyotrophic lateral sclerosis. Cytokine 2003; 23:108-18. [PMID: 12967646 DOI: 10.1016/s1043-4666(03)00217-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Before potential therapeutic strategies for the treatment of amyotrophic lateral sclerosis (ALS) can be advanced to human clinical trials, there is a need to assess them in an animal model that best resembles the disease process. SOD1 G93A mice have close resemblance to familial ALS (fALS) and have been used in this study to evaluate the therapeutic potential of leukaemia inhibitory factor (LIF). LIF action was investigated by assessing three delivery methods: (1) daily subcutaneous injection; (2) through LIF rods placed adjacent to hind limb skeletal muscle and (3) continuous intrathecal infusion. The effect on disease progression was assessed by semi-quantitative and quantitative functional measurements, and histologically on the survival of motor neurons and number of reactive astrocytes. The results show that LIF had no beneficial effects when administered using the three methods of drug delivery. These results suggest that further evaluation of LIF in this transgenic model is required to fully characterize its' therapeutic potential.
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Affiliation(s)
- Sandra J Feeney
- Melbourne Neuromuscular Research Institute, St. Vincent's Hospital, Fitzroy, Victoria 3065, Australia
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Laurà M, Gregson NA, Curmi Y, Hughes RAC. Efficacy of leukemia inhibitory factor in experimental autoimmune neuritis. J Neuroimmunol 2002; 133:56-9. [PMID: 12446008 DOI: 10.1016/s0165-5728(02)00359-4] [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: 11/17/2022]
Abstract
Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that exerts neurotrophic and myotrophic actions. We have investigated the effect of LIF in experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome (GBS). Treatment with LIF at the onset of the disease showed a slight, but not significant, improvement in the clinical course but no effect on nerve histology.
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Affiliation(s)
- M Laurà
- Department of Neurological Sciences, Psychiatry and Anaesthesiology, University of Messina, 98125, Messina, Italy.
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Ishida Y, Ugawa S, Ueda T, Murakami S, Shimada S. Vanilloid receptor subtype-1 (VR1) is specifically localized to taste papillae. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2002; 107:17-22. [PMID: 12414119 DOI: 10.1016/s0169-328x(02)00441-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Pungent sensation of hot peppers is thought to be mediated by vanilloid receptor subtype-1 (VR1), which can be activated by capsaicin, but there is little information regarding its histological localization in the tongue. We examined the immunohistochemical distribution of VR1 in the rat tongue. Intensely labeled VR1-immunoreactive (VR1-IR) fibers were concentrated in the circumvallate, foliate, and fungiform papillae, while sparse VR1-IR fibers were scattered throughout the tongue. VR1-positive taste-bud cells were not observed. Many VR1-positive nerve fibers surrounded the furrows of the circumvallate and foliate papillae, forming plexuses. Some of these VR1-positive fibers penetrated the apical epithelium and the trench wall epithelium, while a few of them entered taste buds. These VR1 distribution patterns resembled those of substance P (SP) and the calcitonin gene-related peptide (CGRP). Double-labeling experiments revealed that most of the VR1-immunoreactivity coexisted with SP- or CGRP-immunoreactivity in the nerve terminals in the circumvallate and foliate papillae. On the other hand, in the fungiform papillae, most of the VR1-IR fibers were positive for SP, but fewer were also positive for CGRP. Although VR1-immunoreactivity was not observed in taste-bud cells, our findings that a large number of VR1-IR fibers concentrated in the taste papillae suggest that capsaicin easily reaches the VR1 nerve terminals because of its lipophilic nature.
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Affiliation(s)
- Yusuke Ishida
- Department of Otorhinolaryngology, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
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Abstract
PURPOSE OF REVIEW Peripheral neuropathy is a common neurotoxic effect of medications. When medications are used to treat life-threatening illnesses, balancing the toxic effects of peripheral neuropathy with the therapeutic benefits of the drug can be difficult. This article examines recent research into the cellular mechanisms associated with neuropathy after treatment with medications to treat cancer, and HIV, and to prevent transplant rejection. RECENT FINDINGS Cisplatin and suramin induce a length, dose, and time-dependent axonal sensorimotor polyneuropathy. Cisplatin and suramin both result in apoptosis in dorsal root ganglion neurons that may partially explain the neuropathy that develops with treatment. In contrast, nerve growth factor prevents initiation of the programmed cell death associated with cisplatin neurotoxicity. Suramin causes accumulation of lamellar inclusion bodies in dorsal root ganglion neurons related to dose of administration and severity of the neuropathy. Nucleoside reverse transcriptase inhibitors affect mitochondrial function and lead to depletion of the nerve's mitochondrial DNA and inhibition of DNA polymerase. These effects on the mitochondrion may be related to the polyneuropathy that develops in these patients. In contrast to the axonal neuropathies, tacrolimus and rarely suramin can result in a demyelinating neuropathy that may mimic Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy. Many of these neuropathies can be reversed by early recognition of the symptoms or by using sensitive electrophysiological testing. In certain instances, specific therapies may ameliorate the neuropathy. Glutamine may reduce paclitaxel-induced toxicity, while some patients with tacrolimus or suramin-induced demyelinating neuropathy may respond to intravenous immunoglobulin or plasmapheresis. SUMMARY Improved understanding of neurotoxic mechanisms in the peripheral nervous system associated with chemotherapeutic and anti-HIV medications, coupled with early improved diagnosis, promises to help limit neurotoxicity associated with these medications.
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Affiliation(s)
- Amanda C Peltier
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, USA
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