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Association of riluzole and dantrolene improves significant recovery after acute spinal cord injury in rats. Spine J 2018; 18:532-539. [PMID: 29155254 DOI: 10.1016/j.spinee.2017.10.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 10/15/2017] [Accepted: 10/26/2017] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Damage to the spinal cord can result in irreversible impairment or complete loss of motor, sensory, and autonomic functions. Riluzole and dantrolene have been shown to provide neuroprotection by reducing neuronal apoptosis after brain and spinal cord injury (SCI) in several animal models of neurologic disorders. As these drugs protect the injured spinal cord through different mechanisms, we investigated the cumulative effects of riluzole and dantrolene. PURPOSE This study aimed to investigate the neuroprotective efficacy of the combined administration of riluzole and dantrolene in experimental thoracic SCI. STUDY DESIGN Twenty-nine Wistar rats were laminectomized at T12 and divided in five groups. Rats in GI (n=6) underwent laminectomy alone and were treated with placebo. Rats in GII (n=6) underwent laminectomy followed by SCI and were treated with placebo. Rats in GIII (n=5) underwent laminectomy followed by SCI and were treated with riluzole and placebo 15 minutes and 1 hour after laminectomy, respectively. Rats in GIV (n=6) underwent laminectomy followed by SCI and were treated with placebo and dantrolene 15 minutes and 1 hour after laminectomy, respectively. Rats in GV (n=6) underwent laminectomy followed by SCI and were treated with riluzole and dantrolene 15 minutes and 1 hour after laminectomy, respectively. A compressive trauma was performed to induce SCI. METHODS Behavioral testing of hind limb function was performed using the Basso Beattie Bresnahan locomotor rating scale, which revealed significant recovery in the group treated with the association of riluzole and dantrolene compared with other groups. After euthanasia, the spinal cord was evaluated using light microscopy and immunochemistry with anti-NeuN and transferase dUTP nick-end-labeling (TUNEL) staining. RESULTS Animals treated with the association of riluzole and dantrolene showed a larger number of NeuN-positive neurons adjacent to the epicenter of injury (p≤.05). Furthermore, the TUNEL staining was similar between animals treated with riluzole and dantrolene and those that did not receive spinal cord trauma (p>.05). CONCLUSIONS These results showed that riluzole and dantrolene have a synergistic effect in neuroprotection after traumatic SCI by decreasing apoptotic cell death.
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Krzyżanowska W, Pomierny B, Filip M, Pera J. Glutamate transporters in brain ischemia: to modulate or not? Acta Pharmacol Sin 2014; 35:444-62. [PMID: 24681894 DOI: 10.1038/aps.2014.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/03/2014] [Indexed: 01/18/2023] Open
Abstract
In this review, we briefly describe glutamate (Glu) metabolism and its specific transports and receptors in the central nervous system (CNS). Thereafter, we focus on excitatory amino acid transporters, cystine/glutamate antiporters (system xc-) and vesicular glutamate transporters, specifically addressing their location and roles in CNS and the molecular mechanisms underlying the regulation of Glu transporters. We provide evidence from in vitro or in vivo studies concerning alterations in Glu transporter expression in response to hypoxia or ischemia, including limited human data that supports the role of Glu transporters in stroke patients. Moreover, the potential to induce brain tolerance to ischemia through modulation of the expression and/or activities of Glu transporters is also discussed. Finally we present strategies involving the application of ischemic preconditioning and pharmacological agents, eg β-lactam antibiotics, amitriptyline, riluzole and N-acetylcysteine, which result in the significant protection of nervous tissues against ischemia.
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Ren L, Fang YN, Zhang AW, Li XL, Wang XJ, Yin Z, Miao JY. Effect of electroacupuncture on the expression of Nav1·1 in rat after acute cerebral ischemia. Neurol Res 2013; 32:763-9. [DOI: 10.1179/016164109x12445616596481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Woodruff TM, Thundyil J, Tang SC, Sobey CG, Taylor SM, Arumugam TV. Pathophysiology, treatment, and animal and cellular models of human ischemic stroke. Mol Neurodegener 2011; 6:11. [PMID: 21266064 PMCID: PMC3037909 DOI: 10.1186/1750-1326-6-11] [Citation(s) in RCA: 384] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Accepted: 01/25/2011] [Indexed: 01/02/2023] Open
Abstract
Stroke is the world's second leading cause of mortality, with a high incidence of severe morbidity in surviving victims. There are currently relatively few treatment options available to minimize tissue death following a stroke. As such, there is a pressing need to explore, at a molecular, cellular, tissue, and whole body level, the mechanisms leading to damage and death of CNS tissue following an ischemic brain event. This review explores the etiology and pathogenesis of ischemic stroke, and provides a general model of such. The pathophysiology of cerebral ischemic injury is explained, and experimental animal models of global and focal ischemic stroke, and in vitro cellular stroke models, are described in detail along with experimental strategies to analyze the injuries. In particular, the technical aspects of these stroke models are assessed and critically evaluated, along with detailed descriptions of the current best-practice murine models of ischemic stroke. Finally, we review preclinical studies using different strategies in experimental models, followed by an evaluation of results of recent, and failed attempts of neuroprotection in human clinical trials. We also explore new and emerging approaches for the prevention and treatment of stroke. In this regard, we note that single-target drug therapies for stroke therapy, have thus far universally failed in clinical trials. The need to investigate new targets for stroke treatments, which have pleiotropic therapeutic effects in the brain, is explored as an alternate strategy, and some such possible targets are elaborated. Developing therapeutic treatments for ischemic stroke is an intrinsically difficult endeavour. The heterogeneity of the causes, the anatomical complexity of the brain, and the practicalities of the victim receiving both timely and effective treatment, conspire against developing effective drug therapies. This should in no way be a disincentive to research, but instead, a clarion call to intensify efforts to ameliorate suffering and death from this common health catastrophe. This review aims to summarize both the present experimental and clinical state-of-the art, and to guide future research directions.
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Affiliation(s)
- Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.
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Armogida M, Giustizieri M, Zona C, Piccirilli S, Nisticò R, Mercuri NB. N-ethyl lidocaine (QX-314) protects striatal neurons against ischemia: an in vitro electrophysiological study. Synapse 2010; 64:161-8. [PMID: 19852070 DOI: 10.1002/syn.20735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this study, we have investigated the neuroprotective actions of the membrane impermeable, lidocaine analog, N-ethyl lidocaine (QX-314) in the striatum. The effects of this drug were compared with those caused by the strictly-related-compound and sodium channel blocker lidocaine. To address this issue, electrophysiological recordings were performed in striatal slices, in control condition (normoxia) and during combined oxygen and glucose deprivation (in vitro ischemia). Either QX-314 or lidocaine induced, to some extent, a protection of the permanent electrophysiological alteration (field potential loss) caused by a period (12 min) of ischemia. Thus, both compounds permitted a partial recovery of the ischemic depression of the corticostriatal transmission and reduced the amplitude of the ischemic depolarization in medium spiny neurons. However, while QX-314, at the effective concentration of 100 microM, slightly reduced the amplitude of the excitatory field potential and did not affect the current-evoked spikes discharge of medium spiny striatal neurons, equimolar lidocaine depressed the field potential and eliminated repetitive spikes on a depolarizing step. On the basis of these observations, our results suggest the use of QX-314 as a neuroprotective agent in ischemic brain disorders.
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Affiliation(s)
- Marta Armogida
- Laboratory of Experimental Neurology, Fondazione Santa Lucia IRCCS, Rome, Italy
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Medico M, Nicosia A, Grech M, Onesta M, Sessa G, Rampello L, Drago F. Riluzole restores motor activity in rats with post-traumatic peripheral neuropathy. Neurosci Lett 2004; 358:37-40. [PMID: 15016429 DOI: 10.1016/j.neulet.2003.12.090] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Accepted: 12/23/2003] [Indexed: 11/23/2022]
Abstract
Riluzole is a presynaptic inhibitor of glutamate release with neuroprotective properties. In order to evaluate the effects of riluzole on motor activity in post-traumatic peripheral neuropathy (PTPN), the sciatic nerve of Wistar male rats was exposed monolaterally and subjected to crushing for one min by a surgical forceps. Animals received an intraperitoneal treatment with riluzole (2, 4 or 8 mg/kg per day), diclofenac (5, 10 or 20 mg/kg) or with vehicle for 3 days. Motor activity and coordination was evaluated in a circular open field and in the rotorod test. The treatment with riluzole stimulated ambulation in PTPN rats and improved their motor performance and coordination. The effect of treatment with riluzole on locomotor activity was greater than that of treatment with diclofenac and was dose-dependent. Furthermore, in contrast to vehicle- and diclofenac-treated rats, animals treated with riluzole showed a long-lasting improvement of locomotor activity as it was assessed 7 days after the end of treatment. These findings suggest that riluzole may improve motor performance in PTPN, and this does not depend on its antinociceptive activity. Its neuroprotective properties are possibly involved in this effect.
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Affiliation(s)
- M Medico
- Department of Experimental and Clinical Pharmacology, University of Catania Medical School, Viale A. Doria 6, 95125 Catania, Italy
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Albo F, Pieri M, Zona C. Modulation of AMPA receptors in spinal motor neurons by the neuroprotective agent riluzole. J Neurosci Res 2004; 78:200-7. [PMID: 15378511 DOI: 10.1002/jnr.20244] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We investigated the interaction of riluzole, a therapeutic agent used in amyotrophic lateral sclerosis (ALS), with alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor channels in mouse spinal motor neurons in culture using whole-cell patch-clamp recording techniques. Kainate elicited concentration-dependent (EC(50) = 35 microM) inward currents in all the patched cells. These responses were mediated primarily through the activation of AMPA receptors with a negligible contribution from kainate receptors, because bath application of 100 microM GYKI53655, a potent noncompetitive AMPA receptor antagonist, completely blocked the kainate-induced currents. Riluzole (0.5-100 microM) reduced in a dose-dependent manner the kainate-induced currents with an IC(50) of 1.54 microM in all tested neurons (n = 25) and this effect was found to be reversible. The response to kainate decreased in the presence of 1 microM riluzole in all spinal motor neurons tested, without changing its EC(50), indicating a noncompetitive mechanism of inhibition. The amplitude of the responses induced by kainate under control condition and during riluzole was a linear function of the membrane potential. The reversal potential of the current was not significantly different in the two experimental conditions, whereas the total conductance of the motor neurons for the currents induced by 100 microM kainate was reduced significantly in the presence of 1 microM riluzole (P < 0.05). These results reveal an interaction of riluzole with glutamatergic neurotransmission in spinal cord motor neurons and can contribute to explain its beneficial effect in the ALS treatment.
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Gilgun-Sherki Y, Panet H, Melamed E, Offen D. Riluzole suppresses experimental autoimmune encephalomyelitis: implications for the treatment of multiple sclerosis. Brain Res 2003; 989:196-204. [PMID: 14556941 DOI: 10.1016/s0006-8993(03)03343-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent studies suggest that glutamate neurotoxicity is involved in the pathogenesis of multiple sclerosis (MS), and that treatment with glutamate receptor (AMPA/kainate) antagonists inhibits experimental autoimmune encephalomyelitis (EAE), the conventional model of MS. Therefore, we examined whether riluzole, an inhibitor of glutamate transmission, affects the pathogenesis and clinical features of MS-like disease in myelin oligodendrocyte glycoprotein (MOG)-induced EAE in mice. Here we report that riluzole (10 mg/kgx2/day, i.p.), administered before and even after the appearance of clinical symptoms, dramatically reduced the clinical severity of MOG-induced EAE, while all the MOG-immunized control mice developed significant clinical manifestations. Moreover, the riluzole-treated mice demonstrated only mild focal inflammation, and less demyelination, compared to MOG-treated mice, using histological methods. Furthermore, riluzole markedly reduced axonal disruption, as assessed by Bielshowesky's silver staining and by antibodies against non-phosphorylated neurofilaments (SMI-32). No difference was detected in the immune system potency, as T-cell proliferative responses to MOG were similar in both groups. In conclusion, our study demonstrates, for the first time, that riluzole can reduce inflammation, demyelination and axonal damage in the CNS and attenuate the clinical severity of MOG-induced EAE. These results suggest that riluzole, a drug used in amyotrophic lateral sclerosis (ALS), might be beneficial for the treatment of MS.
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Affiliation(s)
- Yossi Gilgun-Sherki
- Laboratory of Neurosciences, Felsenstein Medical Research Center and Department of Neurology, Rabin Medical Center-Beilinson Campus, The Sackler School of Medicine, Tel Aviv University, Petah Tikva 49100, Israel
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Jan CR, Lu YC, Jiann BP, Chang HT, Huang JK. Effect of riluzole on cytosolic Ca2+ increase in human osteosarcoma cells. Pharmacology 2002; 66:120-7. [PMID: 12372901 DOI: 10.1159/000063798] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In human osteosarcoma MG63 cells, the effect of the neuroprotective drug riluzole on the intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured using fura-2. Riluzole (50-500 micromol/l) caused a rapid and sustained plateau increase in [Ca(2+)](i) in a concentration-dependent manner (EC(50) = 150 micromol/l). The riluzole-induced rise in [Ca(2+)](i) was prevented by 58 and 20% by extracellular Ca(2+) removal and nifedipine, respectively, but was not changed by La(3+) and verapamil. In Ca(2+)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum (ER) Ca(2+)-ATPase, caused a monophasic increase in [Ca(2+)](i), after which the increasing effect of riluzole on [Ca(2+)](i) was attenuated by 84%; also, pretreatment with riluzole abolished the thapsigargin-induced [Ca(2+)](i) increase. U73122, an inhibitor of phospholipase C, abrogated the ATP (but not riluzole)-induced rise in [Ca(2+)](i). A low concentration (6 micromol/l) of riluzole selectively potentiated the bradykinin (but not ATP and histamine)-induced increase in [Ca(2+)](i). These results suggest that riluzole rapidly increases [Ca(2+)](i) by stimulating both the extracellular Ca(2+) influx via a nifedipine-sensitive pathway and intracellular Ca(2+) release from the ER via an as yet unidentified mechanism(s).
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Affiliation(s)
- Chung-Ren Jan
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
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Cao YJ, Dreixler JC, Couey JJ, Houamed KM. Modulation of recombinant and native neuronal SK channels by the neuroprotective drug riluzole. Eur J Pharmacol 2002; 449:47-54. [PMID: 12163105 DOI: 10.1016/s0014-2999(02)01987-8] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Small conductance, Ca(2+)-activated K(+) channels (SK channels) regulate neuronal excitability. We used patch clamp to study the actions of the neuroprotective drug riluzole on recombinant SK2 channels expressed in HEK293 cells and native SK channels underlying the afterhyperpolarization current (I(AHP)) in cultured hippocampal neurons. External riluzole activated whole-cell SK2 channel currents in HEK293 cells dialyzed with a Ca(2+)-free intracellular solution. When applied to the intracellular aspect of the membrane of giant inside-out patches, riluzole enhanced the membrane current activated by 100 nM Ca(2+) in a reversible and concentration-dependent manner; 30 microM riluzole applied to the intracellular aspect of the patches sensitized the channels to activation by Ca(2+), resulting in a leftward shift of the Ca(2+) activation curve. Riluzole also enhanced the I(AHP) and reduced the spontaneous action potential frequency in chemically stimulated neurons. Modulation of SK channel activity by riluzole may contribute to its cellular, behavioral, and clinical effects.
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Affiliation(s)
- Ying-Jun Cao
- Department of Anesthesia and Critical Care, University of Chicago, 5841 South Maryland Avenue, MC4028, Chicago, IL 60637, USA
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Zona C, Cavalcanti S, De Sarro G, Siniscalchi A, Marchetti C, Gaetti C, Costa N, Mercuri N, Bernardi G. Kainate-induced currents in rat cortical neurons in culture are modulated by riluzole. Synapse 2002; 43:244-51. [PMID: 11835519 DOI: 10.1002/syn.10040] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The action of the neuroprotective and anticonvulsant agent riluzole on kainate-induced currents was studied in rat cortical neurons in primary culture by using the whole-cell configuration of the patch-clamp technique. Kainate elicited macroscopic, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)-sensitive inward currents in all the patched cells and the amplitude of the current was concentration-dependent (EC50= 106 microM). Riluzole decreased the inward currents induced by 100 microM kainate at all holding potentials and the reduction was dose-dependent (IC50= 101 microM). The maximal response to kainate decreased in the presence of 50 microM riluzole, without changing its EC50, indicating a noncompetitive mechanism of inhibition. The amplitude of the responses induced by kainate under control conditions and during riluzole was a linear function of the membrane potential and the reversal potential of the currents was not significantly different in the two experimental conditions. Instead, the total conductance of the cell membrane for the currents induced by 100 microM kainate was significantly reduced in the presence of 50 microM riluzole (P < 0.05). The analysis of the kainate membrane current noise performed under control conditions and during perfusion of 100 microM riluzole revealed that riluzole reduced the probability of kainate-activated ionic channels to be in the open state. Conversely, the unitary conductance of channels, as well as their characteristic time constant, seemed to be unchanged. These results reveal an additional mechanism by which riluzole can interact with glutamatergic neurotransmission and provides further support for the idea that riluzole may prove beneficial in the treatment of central nervous system injuries involving the excitotoxic actions of glutamate.
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Affiliation(s)
- Cristina Zona
- Fisiologia Umana, Università degli Studi di Roma "Tor Vergata," 00133 Rome, Italy.
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Jankovic J, Hunter C. A double-blind, placebo-controlled and longitudinal study of riluzole in early Parkinson's disease. Parkinsonism Relat Disord 2002; 8:271-6. [PMID: 12039422 DOI: 10.1016/s1353-8020(01)00040-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND To the extent that excitotoxicity may play a role in the pathogenesis of certain neurodegenerative disorders, antagonists of glutamate, an excitatory neurotransmitter, should exert neuroprotective effects in these disorders, including Parkinson's disease (PD). METHODS Patients in early stages of PD, not previously treated with levodopa, were randomized to receive riluzole 50mg capsules orally, taken twice daily or a matching placebo. All subjects were evaluated at baseline (pre-treatment), at 1, 3 and 6 months (post-treatment), and following a 6-week washout. After the washout, all subjects were offered an enrollment in an open label, 1-year, extension study. The principal investigator (JJ), however, remained blinded to the original assignment during the entire study. The patients were assessed by the Unified Parkinson's Disease Rating Scale (UPDRS), Activities of Daily Living (ADL), Hoehn & Yahr (HY) stage, and Schwab and England (SE) ADL scale. The quantitative assessments included Movement Time (MT) and Reaction Time (RT). Additionally, the time to initiate dopaminergic therapy was assessed. Safety was determined at each visit by clinical history and examination, a panel of blood safety laboratory tests including complete blood count, chemistry profile, and liver function studies. RESULTS Twenty patients with a mean age of 62+/-9.02 (range: 46-73) years and mean duration of symptoms of 18+/-9.53 (range: 6-36) months were enrolled. One patient withdrew from the study because he needed more aggressive treatment of his symptoms. Analysis of the efficacy variables showed no meaningful symptomatic effect of riluzole on UPDRS score. Likewise, there was no significant change in the median HY stage, SE ADL rating, or the MT/RT. Seventeen patients (mean age 62+/-9.26) elected to continue in the open label extension study. Although the observed deterioration in UPDRS scores seemed to be more pronounced in the placebo group than in the riluzole group, the difference did not reach statistical significance. There was no statistically significant difference in the latency between enrollment and start of symptomatic therapy when patients initially treated with riluzole were compared to those initially treated with placebo (8.3 vs 9 months). CONCLUSIONS This pilot and extension study showed that riluzole, 100mg/day, was well tolerated in patients with early PD. No evidence of symptomatic effect of riluzole was observed. Because of the exploratory nature of the design and small size of the study, it was not possible to determine whether riluzole affected the natural history of PD. The encouraging results from our study, however, suggest that larger, longitudinal studies are warranted.
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Affiliation(s)
- J Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, 6550 Fannin Smith 1801, Houston, TX 77030, USA.
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Yoshida M, Noguchi E, Tsuru N, Ohkoshi N. Effect of riluzole on the acquisition and expression of amygdala kindling. Epilepsy Res 2001; 46:101-9. [PMID: 11463511 DOI: 10.1016/s0920-1211(01)00251-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PURPOSE Riluzole possesses various synaptic effects including an inhibitory action on glutamate release. The drug has been shown to inhibit kindled seizures, while its effect on the acquisition of kindling has not been reported. We investigated effects of riluzole on the kindling development in addition to effects on kindled seizures. METHODS A bipolar electrode was implanted in the right amygdala of rats. Riluzole was injected intraperitoneally 30 min before kindling stimulation. To investigate effects of riluzole on the kindling development, rats were stimulated once daily for the drug session of 14 days at a current of 200 microA, 60 Hz, 1 ms for 2 s and thereafter stimulated without drugs (drug-free session) until completion of kindling. Seizure ranks and after discharge duration were observed every day. To investigate effects of riluzole on kindled seizures, fully-kindled rats were stimulated at the current of generalized seizure threshold (GST) before and after the administration of riluzole. Seizure ranks and after discharge duration were measured. GST after the treatment was also determined. RESULTS The number of stimuli required for the first appearance of stage five seizure was significantly larger in rats treated with 8 mg/kg of riluzole than in vehicle controls. Riluzole at a dose of 8 mg/kg significantly retarded the development of seizure stages in the drug session. By comparison, effects on the duration of after discharge was relatively mild, though significantly different from the vehicle control. Riluzole at a dose of either 4 or 8 mg/kg markedly inhibited behavioral seizures and reduced the duration of after discharge in kindled seizures provoked by GST. The drug also significantly increased GST at both doses, suggesting that the anticonvulsant effects were attributed to the increase in GST. CONCLUSION It was demonstrated that inhibitory effects of riluzole on both kindled seizures and the development of behavioral seizures in kindling acquisition with relatively mild correlation to afterdischarge duration. These effects might be attributed to inhibitory actions of riluzole on glutamate release and NMDA-receptor mediated events.
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Affiliation(s)
- M Yoshida
- Department of Neurology, Tsukuba College of Technology Kasuga 4-12-7, City of Tukuba, 305-0821, Ibaraki, Japan
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Ko H, Zeller M, Gabriel S, Graulich J, Heinemann U, Obladen M. Mild postischemic hypothermia is neuroprotective in the immature rat neocortex slice. Brain Res 2001; 894:297-300. [PMID: 11251204 DOI: 10.1016/s0006-8993(00)03188-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Mild hypothermia as an intervention after perinatal asphyxia may prevent neurological damage in the newborn. We used stimulus-induced field potentials to monitor recovery from oxygen and glucose deprivation (OGD) in neocortex slices of 6-8-day-old wistar rats. OGD after a latency of 10.7+/-2.1 min (mean+/-S.E.) resulted in an anoxic depolarisation with an amplitude of 5.4+/-2.4 mV. Mild hypothermia of 31 degrees C (vs. 35 degrees C in the control group) was applied for 60 min after end of OGD. The 20, 40, 60 and 80% recovery of the field potential amplitude was significantly faster in the hypothermia group in comparison to the control group. These data indicate that mild postischemic hypothermia may have neuroprotective effects after perinatal asphyxia.
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Affiliation(s)
- H Ko
- Department of Neonatology, Charité Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353, Berlin, Germany.
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De Sarro G, Siniscalchi A, Ferreri G, Gallelli L, De Sarro A. NMDA and AMPA/kainate receptors are involved in the anticonvulsant activity of riluzole in DBA/2 mice. Eur J Pharmacol 2000; 408:25-34. [PMID: 11070180 DOI: 10.1016/s0014-2999(00)00709-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The anticonvulsant activity of riluzole against sound-induced seizures was studied in the DBA/2 mouse model. Riluzole (0.1-4 mg kg(-1), intraperitoneal (i.p.)) produced dose-dependent effects with ED(50) values for the suppression of tonic, clonic and wild running phases of 0.72, 1.38 and 2.71 mg kg(-1), respectively. Riluzole also protected DBA/2 mice from seizures induced by an intracerebroventricular (i.c.v.) injection of N-methyl-D-aspartate (NMDA) with ED(50) values of 3.03 and 5.0 mg kg(-1) for tonus and clonus, respectively. Pretreatment with glycine, an agonist to the glycine/NMDA receptors, shifted the dose-response effect of riluzole to the right (ED(50)=6.53 against tonus and 9.34 mg kg(-1) vs. clonus). Similarly, D-serine, an agonist at the glycine site, shifted the ED(50) of riluzole against the tonic component of audiogenic seizures from 0.72 to 1.97, and that against clonus from 1.38 to 2.77 mg kg(-1). Riluzole was also potent to prevent seizures induced by administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), an AMPA/kainate receptor agonist (ED(50)=1.80 and 3.35 mg kg(-1), against tonus and clonus, respectively). Pretreatment with aniracetam, a positive allosteric modulator of AMPA/kainate receptors, shifted the dose-response curve of riluzole to the right (ED(50)=1.78 against tonus and 2.58 mg kg(-1) vs. clonus). The data indicate that riluzole is an effective anticonvulsant drug in the genetic model of seizure-prone DBA/2 mice. Our findings suggest that the anticonvulsant properties of riluzole depend upon its interaction with neurotransmission mediated by both the glycine/NMDA and the AMPA/kainate receptor complex.
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Affiliation(s)
- G De Sarro
- Department of Experimental and Clinical Medicine, Faculty of Medicine and Surgery, University of Catanzaro Magna Graecia, Policlinico Mater Domini, Via T. Campanella, 88100 Catanzaro, Italy.
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