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Xia Y, Lai W, Sha L, Duan Y, Chen L. Causal link between oxidative stress and epilepsy: A two-sample Mendelian randomization study. Brain Behav 2024; 14:e3549. [PMID: 38849979 PMCID: PMC11161392 DOI: 10.1002/brb3.3549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/18/2024] [Accepted: 02/21/2024] [Indexed: 06/09/2024] Open
Abstract
BACKGROUND Although a growing body of research has indicated a strong link between oxidative stress and epilepsy, the exact nature of their interaction remains elusive. To elucidate this intricate relationship, we conducted a bidirectional Mendelian randomization (MR) analysis employing two independent datasets. METHODS A two-sample MR analysis was performed using instrumental variables derived from genome-wide association study summary statistics of oxidative stress injury biomarkers (OSIB) and epilepsy. The OSIBs were selected from eight primary metabolic pathways associated with oxidative stress. Additionally, seven distinct epilepsy phenotypes were considered, which encompassed all epilepsy, generalized epilepsy, generalized tonic-clonic seizures, focal epilepsy, focal epilepsy with hippocampal sclerosis (focal HS), focal epilepsy with lesions other than HS (focal NHS), and lesion-negative focal epilepsy. Causal estimates were computed using the inverse-variance weighted method or the Wald ratio method, and the robustness of causality was assessed through sensitivity analyses. RESULTS For OSIB and epilepsy, 520 and 23 genetic variants, respectively, were selectively extracted as instrumental variants. Genetically predicted higher kynurenine level was associated with a decreased risk of focal epilepsy (odds ratio [OR] 1.950, 95% CI 1.373-2.528, p = .023) and focal NHS (OR 1.276, 95% CI 1.100-1.453, p = .006). For reverse analysis, there was a suggestive effect of focal NHS on urate (OR 1.19 × 1015, 95% CI 11.19 × 1015 to 1.19 × 1015, p = .0000746) and total bilirubin (Tb) (OR 4.98, 95% CI 3.423-6.543, p = .044). In addition, genetic predisposition to focal HS was associated with higher Tb levels (OR 9.83, 95% CI 7.77-11.888, p = .034). CONCLUSION This MR study provides compelling evidence of a robust association between oxidative stress and epilepsy, with a notable emphasis on a causal relationship between oxidative stress and focal epilepsy. Additional research is warranted to confirm the connection between oxidative stress and the risk of epilepsy and to unravel the underlying mechanisms.
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Affiliation(s)
- Yilin Xia
- Department of Neurology, West China HospitalSichuan UniversityChengduChina
| | - Wanlin Lai
- Department of Neurology, West China HospitalSichuan UniversityChengduChina
| | - Leihao Sha
- Department of Neurology, West China HospitalSichuan UniversityChengduChina
| | - Yifei Duan
- Department of Neurology, West China HospitalSichuan UniversityChengduChina
| | - Lei Chen
- Department of Neurology, West China HospitalSichuan UniversityChengduChina
- Pazhou LabGuangzhouChina
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2
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Dias L, Pochmann D, Lemos C, Silva HB, Real JI, Gonçalves FQ, Rial D, Gonçalves N, Simões AP, Ferreira SG, Agostinho P, Cunha RA, Tomé AR. Increased Synaptic ATP Release and CD73-Mediated Formation of Extracellular Adenosine in the Control of Behavioral and Electrophysiological Modifications Caused by Chronic Stress. ACS Chem Neurosci 2023; 14:1299-1309. [PMID: 36881648 PMCID: PMC10080657 DOI: 10.1021/acschemneuro.2c00810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Increased ATP release and its extracellular catabolism through CD73 (ecto-5'-nucleotidase) lead to the overactivation of adenosine A2A receptors (A2AR), which occurs in different brain disorders. A2AR blockade blunts mood and memory dysfunction caused by repeated stress, but it is unknown if increased ATP release coupled to CD73-mediated formation of extracellular adenosine is responsible for A2AR overactivation upon repeated stress. This was now investigated in adult rats subject to repeated stress for 14 consecutive days. Frontocortical and hippocampal synaptosomes from stressed rats displayed an increased release of ATP upon depolarization, coupled to an increased density of vesicular nucleotide transporters and of CD73. The continuous intracerebroventricular delivery of the CD73 inhibitor α,β-methylene ADP (AOPCP, 100 μM) during restraint stress attenuated mood and memory dysfunction. Slice electrophysiological recordings showed that restraint stress decreased long-term potentiation both in prefrontocortical layer II/III-layer V synapses and in hippocampal Schaffer fibers-CA1 pyramid synapses, which was prevented by AOPCP, an effect occluded by adenosine deaminase and by the A2AR antagonist SCH58261. These results indicate that increased synaptic ATP release coupled to CD73-mediated formation of extracellular adenosine contributes to mood and memory dysfunction triggered by repeated restraint stress. This prompts considering interventions decreasing ATP release and CD73 activity as novel strategies to mitigate the burden of repeated stress.
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Affiliation(s)
- Liliana Dias
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,FMUC─Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Daniela Pochmann
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Cristina Lemos
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Henrique B Silva
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Joana I Real
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Francisco Q Gonçalves
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Daniel Rial
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Nélio Gonçalves
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Ana Patrícia Simões
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Samira G Ferreira
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Paula Agostinho
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,FMUC─Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,FMUC─Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Angelo R Tomé
- CNC─Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra, Portugal
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3
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Strogulski NR, Stefani MA, Böhmer AE, Hansel G, Rodolphi MS, Kopczynski A, de Oliveira VG, Stefani ET, Portela JV, Schmidt AP, Oses JP, Smith DH, Portela LV. Cerebrospinal fluid purinomics as a biomarker approach to predict outcome after severe traumatic brain injury. J Neurochem 2022; 161:173-186. [PMID: 35157328 PMCID: PMC9035090 DOI: 10.1111/jnc.15590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/19/2022] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Abstract
Severe traumatic brain injury (TBI) is associated with high rates of mortality and long-term disability linked to neurochemical abnormalities. Although purine-derivatives play important roles in TBI pathogenesis in preclinical models, little is known about potential changes in purine levels and their implications in human TBI. We assessed cerebrospinal fluid (CSF) levels of purines in severe TBI patients as potential biomarkers that predict mortality and long-term dysfunction. This was a cross-sectional study performed in 17 severe TBI patients (Glasgow Coma Scale < 8) and 51 controls. Two to four hours after admission to ICU, patients were submitted to ventricular drainage and CSF collection for quantification of adenine and guanine purine-derivatives by HPLC. TBI patients survival was followed up to 3 days from admission. A neurofunctional assessment was performed through the modified Rankin Scale (mRS) two years after ICU admission. Purine levels were compared between control and TBI patients, and between surviving and non-surviving patients. Relative to controls, TBI patients presented increased CSF levels of GDP, guanosine, adenosine, inosine, hypoxanthine, and xanthine. Further, GTP, GDP, IMP, and xanthine levels were different between surviving and non-surviving patients. Among the purines, guanosine was associated with improved mRS (p=0.042; r= -0.506). Remarkably, GTP displayed predictive value (AUC=0.841, p=0.024) for discriminating survival vs. non-survival patients up to three days from admission. These results support TBI-specific purine signatures, suggesting GTP as a promising biomarker of mortality, and guanosine as an indicator of long-term functional disability.
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Affiliation(s)
- Nathan R Strogulski
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Marco Antonio Stefani
- Laboratory of Neuroanatomy, Departamento de Ciências Morfológicas, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Ana Elisa Böhmer
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gisele Hansel
- Neuroinflammation and Neuroimmunology Laboratory, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Marcelo S Rodolphi
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Afonso Kopczynski
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Vitória G de Oliveira
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Eduarda T Stefani
- Laboratory of Neuroanatomy, Departamento de Ciências Morfológicas, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Juliana V Portela
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - André P Schmidt
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.,Department of Anesthesia and Perioperative Medicine, Hospital de Clínicas de Porto Alegre (HCPA), UFRGS, Porto Alegre, RS, Brazil. Department of Anesthesia, Santa Casa de Porto Alegre, Universidade Federal de Ciências Médicas de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil. Department of Anesthesia, Hospital Nossa Senhora da Conceição, Porto Alegre, RS, Brazil
| | - Jean Pierre Oses
- Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS, Brazil
| | - Douglas H Smith
- Penn Center for Brain Injury and Repair and Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Luis V Portela
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
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4
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Nedeljkovic N. Complex regulation of ecto-5'-nucleotidase/CD73 and A 2AR-mediated adenosine signaling at neurovascular unit: A link between acute and chronic neuroinflammation. Pharmacol Res 2019; 144:99-115. [PMID: 30954629 DOI: 10.1016/j.phrs.2019.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/01/2019] [Accepted: 04/03/2019] [Indexed: 12/20/2022]
Abstract
The review summarizes available data regarding the complex regulation of CD73 at the neurovascular unit (NVU) during neuroinflammation. Based on available data we propose the biphasic pattern of CD73 regulation at NVU, with an early attenuation and a postponed up-regulation of CD73 activity. Transient attenuation of CD73 activity on leukocyte/vascular endothelium and leukocyte/astrocyte surface, required for the initiation of a neuroinflammatory response, may be effectuated either by catalytic inhibition of CD73 and/or by shedding of the CD73 molecule from the cell surface, while postponed induction of CD73 is effectuated by transcriptional up-regulation of Nt5e and posttranslational modifications. Neuroinflammatory conditions are also associated with significant enhancement and gain-of-function of A2AR-mediated adenosine signaling. However, in contrast to the temporary prevalence of A2AR over A1R signaling during an acute inflammatory response, prolonged induction of A2AR and resulting perpetual CD73/A2AR coupling may be a contributing factors in the transition between acute and chronic neuroinflammation. Thus, pharmacological targeting of the CD73/A2AR axis may attenuate inflammatory response and ameliorate neurological deficits in chronic neuroinflammatory conditions.
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Affiliation(s)
- Nadezda Nedeljkovic
- Department of General Physiology and Biophysics, Faculty of Biology University of Belgrade, Studentski trg 3, Belgrade 11001, Serbia.
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5
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Lakatos RK, Dobolyi Á, Kovács Z. Uric acid and allopurinol aggravate absence epileptic activity in Wistar Albino Glaxo Rijswijk rats. Brain Res 2018; 1686:1-9. [PMID: 29457994 DOI: 10.1016/j.brainres.2018.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 01/05/2018] [Accepted: 02/10/2018] [Indexed: 11/18/2022]
Abstract
Uric acid has a role in several physiological and pathophysiological processes. For example, uric acid may facilitate seizure generalization while reducing uric acid level may evoke anticonvulsant/antiepileptic effects. Allopurinol blocks the activity of xanthine oxidase, by which allopurinol inhibits catabolism of hypoxanthine to xanthine and uric acid and, as a consequence, decreases the level of uric acid. Although the modulation of serum uric acid level is a widely used strategy in the treatment of certain diseases, our knowledge regarding the effects of uric acid on epileptic activity is far from complete. Thus, the main aim of this study was the investigation of the effect of uric acid on absence epileptic seizures (spike-wave discharges: SWDs) in a model of human absence epilepsy, the Wistar Albino Glaxo/Rijswijk (WAG/Rij) rat. We investigated the influence of intraperitoneally (i.p.) injected uric acid (100 mg/kg and 200 mg/kg), allopurinol (50 mg/kg and 100 mg/kg), a cyclooxygenase 1 and 2 (COX-1 and COX-2) inhibitor indomethacin (10 mg/kg) and inosine (500 mg/kg) alone and the combined application of allopurinol (50 mg/kg) with uric acid (100 mg/kg) or inosine (500 mg/kg) as well as indomethacin (10 mg/kg) with uric acid (100 mg/kg) and inosine (500 mg/kg) with uric acid (100 mg/kg) on absence epileptic activity. We demonstrated that both uric acid and allopurinol alone significantly increased the number of SWDs whereas indomethacin abolished the uric acid-evoked increase in SWD number. Our results suggest that uric acid and allopurinol have proepileptic effects in WAG/Rij rats.
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Affiliation(s)
- Renáta Krisztina Lakatos
- Institute of Biology, University of Pécs, Pécs, Hungary; Savaria Department of Biology, Savaria University Centre, ELTE Eötvös Loránd University, Szombathely, Hungary.
| | - Árpád Dobolyi
- Laboratory of Neuromorphology and Human Brain Tissue Bank, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary; MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences and Eötvös Loránd University, Budapest, Hungary.
| | - Zsolt Kovács
- Savaria Department of Biology, Savaria University Centre, ELTE Eötvös Loránd University, Szombathely, Hungary.
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6
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León-Navarro DA, Albasanz JL, Martín M. Hyperthermia-induced seizures alter adenosine A1
and A2A
receptors and 5′-nucleotidase activity in rat cerebral cortex. J Neurochem 2015; 134:395-404. [DOI: 10.1111/jnc.13130] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 12/20/2022]
Affiliation(s)
- David Agustín León-Navarro
- Departamento de Química Inorgánica; Orgánica y Bioquímica; Facultad de Ciencias y Tecnologías Químicas; Centro Regional de Investigaciones Biomédicas; Universidad de Castilla-La Mancha; Avenida Camilo José Cela; Ciudad Real Spain
| | - José L. Albasanz
- Departamento de Química Inorgánica; Orgánica y Bioquímica; Facultad de Ciencias y Tecnologías Químicas; Centro Regional de Investigaciones Biomédicas; Universidad de Castilla-La Mancha; Avenida Camilo José Cela; Ciudad Real Spain
| | - Mairena Martín
- Departamento de Química Inorgánica; Orgánica y Bioquímica; Facultad de Ciencias y Tecnologías Químicas; Centro Regional de Investigaciones Biomédicas; Universidad de Castilla-La Mancha; Avenida Camilo José Cela; Ciudad Real Spain
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7
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Zhang YF, Li SL, Xiong TQ, Yang LB, Li YN, Tan BH, Liu Q, Li YC. The rearrangement of filamentous actin in mossy fiber synapses in pentylenetetrazol-kindled C57BL/6 mice. Epilepsy Res 2013; 108:20-8. [PMID: 24275550 DOI: 10.1016/j.eplepsyres.2013.10.019] [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] [Received: 06/08/2013] [Revised: 09/04/2013] [Accepted: 10/31/2013] [Indexed: 01/16/2023]
Abstract
Chemical kindling, as an experimental model of epileptogenesis, is induced by repetitive administration of subconvulsive amount of excitatory drugs. Kindled mice do not typically display spontaneous recurrent seizures, but are instead characterized by enhanced seizure susceptibility to convulsive stimulations. In order to provide insights into the aberrant synaptic plasticity during kindling, this study investigated the effect of pentylenetetrazol (PTZ) kindling on filamentous actin (F-actin) in mossy fiber synapses in C57BL/6 mice. Phalloidin labeling of F-actin showed that F-actin puncta were increased in number in the stratum lucidum of CA3 region in the hippocampus after kindling. The rearrangement of F-actin seemed to occur presynaptically, since synapsin I, a specific marker for mossy fiber terminals, was also up-regulated. Such subtle structural modifications occurring in the synapses are thought to contribute to the long-lasting increased sensitivity in the PTZ-kindled C57BL/6 mice.
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Affiliation(s)
- Yan-Feng Zhang
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China; Department of Neurology, First Affiliated Hospital of Jilin University, Changchun, Jilin Province 130021, PR China; Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Shu-Lei Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Tian-Qing Xiong
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Li-Bin Yang
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Yong-Nan Li
- Department of Neurology, Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province 150001, PR China
| | - Bai-Hong Tan
- Laboratory Teaching Center of Basic Medicine, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Qun Liu
- Department of Neurology, First Affiliated Hospital of Jilin University, Changchun, Jilin Province 130021, PR China.
| | - Yan-Chao Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China.
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da Silveira VG, da Silva RS, de Paula Cognato G, Capiotti KM, Figueiró F, Bogo MR, Bonan CD, Perry MLS, Battastini AMO. A ketogenic diet did not prevent effects on the ectonucleotidases pathway promoted by lithium-pilocarpine-induced status epilepticus in rat hippocampus. Metab Brain Dis 2012; 27:471-8. [PMID: 22945235 DOI: 10.1007/s11011-012-9333-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 08/19/2012] [Indexed: 10/27/2022]
Abstract
A Ketogenic Diet (KD) mimics the anticonvulsant effects of fasting, which are known to suppress seizures. The purinergic system has been investigated in the matter of epilepsy development, especially the nucleoside adenosine, which has been considered a natural brain anticonvulsant. During epileptic seizures, extracellular adenosine concentration rises rapidly to micromolar levels. Adenosine can exert its anticonvulsant functions, after its release by nucleoside bidirectional transport, or by production through the sequential catabolism of ATP by ectonucleotidases, such as E-NTPDases (ectonucleoside triphosphate diphosphohydrolases) and ecto-5'-nucleotidase. Here, we have investigated the effect of a ketogenic diet on the nucleotide hydrolysis and NTPDases expression in the lithium-pilocarpine (Li-Pilo) model of epilepsy. For the induction of Status Epileticus (SE), 21-day-old female Wistar rats received an i.p. injection of lithium chloride (127 mg/kg) and 18-19 h later an i.p. injection of pilocarpine hydrochloride (60 mg/kg). The control groups received an injection of saline. After induction of SE, the control and Li-Pilo groups received standard or ketogenic diets for 6 weeks. The lithium-pilocarpine exposure affected the ATP (a decrease of between 8 % and 16 %) and ADP (an increase of between 18 % and 22 %) hydrolysis in both groups whereas the diet did not impact the nucleotide hydrolysis. NTPDase2 and 3 mRNA expressions decreased in the Li-Pilo group (41 % and 42 %). This data highlights the participation of the purinergic system in the pathophysiology of this model of epilepsy, since nucleotide hydrolysis and NTPDase expressions were altered by Li-Pilo exposure, with no significant effects of the ketogenic diet. However, the interaction between purinergic signaling and a ketogenic diet on epilepsy still needs to be better elucidated.
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Affiliation(s)
- Vanessa Gass da Silveira
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, CEP 90035-003, Porto Alegre, RS, Brazil
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9
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Acute creatine administration improves mitochondrial membrane potential and protects against pentylenetetrazol-induced seizures. Amino Acids 2012; 44:857-68. [DOI: 10.1007/s00726-012-1408-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Accepted: 09/24/2012] [Indexed: 11/26/2022]
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10
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Czarnecka J, Roszek K, Jabłoński A, Smoliński DJ, Komoszyński M. Some aspects of purinergic signaling in the ventricular system of porcine brain. Acta Vet Scand 2011; 53:54. [PMID: 21995888 PMCID: PMC3213016 DOI: 10.1186/1751-0147-53-54] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 10/13/2011] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system. RESULTS Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (Sus scrofa domestica). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine. CONCLUSIONS Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.
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11
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Profile of nucleotide catabolism and ectonucleotidase expression from the hippocampi of neonatal rats after caffeine exposure. Neurochem Res 2011; 37:23-30. [PMID: 21842269 DOI: 10.1007/s11064-011-0577-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/18/2011] [Accepted: 08/04/2011] [Indexed: 10/17/2022]
Abstract
Nucleotides and nucleosides play an important role in neurodevelopment acting through specific receptors. Ectonucleotidases are the major enzymes involved in controlling the availability of purinergic receptors ligands. ATP is co-released with several neurotransmitters and is the most important source of extracellular adenosine by catabolism exerted by ectonucleotidases. The main ectonucleotidases are named NTPDases (1-8) and 5'-nucleotidase. Adenosine is a powerful modulator of neurotransmitter release. Caffeine blocks adenosine receptor activity as well as adenosine-mediated neuromodulation. Considering the susceptibility of the immature brain to caffeine and the need for correct purinergic signaling during fetal development, we have analyzed the effects of caffeine exposure during gestational and lactational periods on nucleotide degradation and ectonucleotidase expression from the hippocampi of 7-, 14- and 21-days-old rats. Nucleotides hydrolysis was assessed by colorimetric determination of inorganic phosphate released. Ectonucleotidases expression was performed by RT-PCR. ATP and ADP hydrolysis displayed parallel age-dependent decreases in both control and caffeine-treated groups. AMP hydrolysis increased with caffeine treatment in 7-days-old rats (75%); although there was no significant difference in AMP hydrolysis between control (non caffeine-treated) rats and 14- or 21-days caffeine-treated rats. ADP hydrolysis was not affected by caffeine treatment. Caffeine treatment in 7- and 14-days-old rats decreased ATP hydrolysis when compared to the control group (19% and 60% decrease, respectively), but 21-days-treated rats showed an increase in ATP hydrolysis (39%). Expression levels of NTPDase 1 and 5 decreased in hippocampi of caffeine-treated rats. The expression of 5'-nucleotidase was not affected after caffeine exposure. The changes observed in nucleotide hydrolysis and ectonucleotidases expression could promote subtle effects on normal neural development considering the neuromodulatory role of adenosine.
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Rico EP, Rosemberg DB, Langoni ADS, Souto AA, Dias RD, Bogo MR, Bonan CD, Souza DO. Chronic ethanol treatment alters purine nucleotide hydrolysis and nucleotidase gene expression pattern in zebrafish brain. Neurotoxicology 2011; 32:871-8. [PMID: 21704070 DOI: 10.1016/j.neuro.2011.05.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 04/12/2011] [Accepted: 05/23/2011] [Indexed: 12/20/2022]
Abstract
Ethanol is a widely consumed drug that acts on the central nervous system (CNS), modifying several signal transduction pathways activated by hormones and neurotransmitters. The zebrafish is an experimental model for the study of human diseases and the use of this species in biochemical and behavioral studies on alcoholism and alcohol-dependence has increased recently. However, there are no data concerning the effects of chronic ethanol exposure on the purinergic system, where extracellular nucleotides act as signaling molecules. Purinergic signaling is controlled by a group of enzymes named ectonucleotidases, which include NTPDases and ecto-5'-nucleotidase already characterized in zebrafish brain. The aim of this study was to evaluate nucleotide hydrolysis by NTPDases and ecto-5'-nucleotidase after long-term ethanol exposure. Additionally, the gene expression patterns of NTPDases1-3 and 5'-nucleotidase were determined. Animals were exposed to 0.5% ethanol for 7, 14, and 28 days. There were no significant changes in ATP and GTP hydrolysis after all treatments. However, a decrease in ADP (46% and 34%) and GDP (48% and 36%) hydrolysis was verified after 7 and 14 days, respectively. After 7 and 14 days of ethanol exposure, a significant decrease in AMP hydrolysis (48% and 36%) was also observed, whereas GMP hydrolysis was inhibited only after 7 days (46%). NTPDase2_mv and NTPDase3 mRNA transcript levels decreased after 7 and 14 days, respectively. In contrast, ethanol increased NTPDase1, NTPDase2_mq, and NTPDase3 transcript levels after 28 days of exposure. NTPDase2_mg and 5'-nucleotidase gene expression was not altered. Therefore, the ectonucleotidase pathway may be a target of chronic ethanol toxicity and the regulation of purinergic system could play a key role in the neurochemical mechanisms underlying the effects of ethanol on the CNS.
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Affiliation(s)
- Eduardo Pacheco Rico
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil.
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Cognato GP, Vuaden FC, Savio LEB, Bellaver B, Casali E, Bogo MR, Souza DOG, Sévigny J, Bonan CD. Nucleoside triphosphate diphosphohydrolases role in the pathophysiology of cognitive impairment induced by seizure in early age. Neuroscience 2011; 180:191-200. [PMID: 21315806 DOI: 10.1016/j.neuroscience.2011.01.065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/31/2011] [Accepted: 01/31/2011] [Indexed: 11/15/2022]
Abstract
Studies have shown that seizures in young animals lead to later cognitive deficits. There is evidence that long-term potentiation (LTP) and long-term depression (LTD) might contribute to the neural basis for learning and memory mechanism and might be modulated by ATP and/or its dephosphorylated product adenosine produced by a cascade of cell-surface transmembrane enzymes, such as E-NTPDases (ecto-nucleoside triphosphate diphosphohydrolases) and ecto-5'-nucleotidase. Thus, we have investigated if hippocampal ecto-nucleotidase activities are altered at different time periods after one episode of seizure induced by kainic acid (KA) in 7 days old rats. We also have evaluated if 90 day-old rats previously submitted to seizure induced by KA at 7 days of age presented cognitive impairment in Y-maze behavior task. Our results have shown memory impairment of adult rats (Postnatal day 90) previously submitted to one single seizure episode in neonatal period (Postnatal day 7), which is accompanied by an increased ATP hydrolysis in hippocampal synaptosomes. The metabolism of ATP evaluated by HPLC confirmed that ATP hydrolysis was faster in adult rats treated with KA in neonatal period than in controls. Surprisingly, the mRNA and protein levels as seen by PCR and Western blot, respectively, were not altered by the KA administration in early age. Since we have found an augmented hydrolysis of ATP and this nucleotide seems to be important to LTP induction, we could assume that impairment of memory and learning observed in adult rats which have experienced a convulsive episode in postnatal period may be a consequence of the increased ATP hydrolysis. These findings correlate the purinergic signaling to the cognitive deficits induced by neonatal seizures and contribute to a better understanding about the mechanisms of seizure-induced memory dysfunction.
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Affiliation(s)
- G P Cognato
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Avenida Ramiro Barcelos, 2600 Anexo, 90035-000 Porto Alegre, Rio Grande do Sul, Brazil
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Dale N, Frenguelli BG. Release of adenosine and ATP during ischemia and epilepsy. Curr Neuropharmacol 2010; 7:160-79. [PMID: 20190959 PMCID: PMC2769001 DOI: 10.2174/157015909789152146] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/15/2009] [Accepted: 05/01/2009] [Indexed: 12/17/2022] Open
Abstract
Eighty years ago Drury & Szent-Györgyi described the actions of adenosine, AMP (adenylic acid) and ATP (pyrophosphoric or diphosphoric ester of adenylic acid) on the mammalian cardiovascular system, skeletal muscle, intestinal and urinary systems. Since then considerable insight has been gleaned on the means by which these compounds act, not least of which in the distinction between the two broad classes of their respective receptors, with their many subtypes, and the ensuing diversity in cellular consequences their activation invokes. These myriad actions are of course predicated on the release of the purines into the extracellular milieu, but, surprisingly, there is still considerable ambiguity as to how this occurs in various physiological and pathophysiological conditions. In this review we summarise the release of ATP and adenosine during seizures and cerebral ischemia and discuss mechanisms by which the purines adenosine and ATP may be released from cells in the CNS under these conditions.
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Affiliation(s)
- Nicholas Dale
- Department of Biological Sciences, University of Warwick, Coventry, CV4 7AL, UK
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Neurophysiological study on possible protective and therapeutic effects of Sidr (Zizyphus spina-christi L.) leaf extract in male albino rats treated with pentylenetetrazol. Saudi J Biol Sci 2010; 17:269-74. [PMID: 23961090 PMCID: PMC3730870 DOI: 10.1016/j.sjbs.2010.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 04/25/2010] [Accepted: 05/16/2010] [Indexed: 11/21/2022] Open
Abstract
In this study, anti-convulsant effect of Sidr leaf extract was examined by using pentylenetetrazol (PTZ) model on male albino rat by evaluating the changes in norepinephrine (NE), dopamine (DA) and serotonin (5-HT) contents in different brain regions (cerebellum, brainstem, striatum, cerebral cortex, hypothalamus and hippocampus). The administration of subconvulsive dose of PTZ (40 mg/kg i.p.) every other day for 9 days caused a significant decrease in monoamine content in different brain areas, this is may be due to the increase in nitric oxide levels, although antagonized the GABAA receptors which led to neurotransmitter release so the content is decreased. Administration of PTZ after treatment with Sidr (50 mg/kg i.p.) leaf extract for 3 weeks as a protective group and administration of Sidr leaf extract for 3 weeks after treatment of PTZ as a therapeutic group caused significant increase in NE, DA, and 5-HT contents in all tested brain regions at most of the time intervals studied. This may be due to the presence of peptide and cyclopeptide alkaloids in the extract which inhibit neurotransmitter activity which led to the inhibition of neurotransmitter release. From these results, we can say that the Sidr leaf extract has neuroprotective and therapeutic roles against pentylenetetrazol convulsant effect.
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Rozisky JR, da Silva RS, Adachi LS, Capiotti KM, Ramos DB, Bogo MR, Bonan CD, Sarkis JJF, Torres ILDS. Neonatal morphine exposure alters E-NTPDase activity and gene expression pattern in spinal cord and cerebral cortex of rats. Eur J Pharmacol 2010; 642:72-6. [PMID: 20553911 DOI: 10.1016/j.ejphar.2010.05.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/25/2010] [Accepted: 05/23/2010] [Indexed: 12/25/2022]
Abstract
The neonate opioid system has been frequently investigated, and studies have shown that exposure to drugs in early life can have implications for nervous system development. It has been proposed that adenosine is involved in opioid antinociception, and ATP is involved in central and peripheral mechanisms of nociception. Extracellular nucleotides can be hydrolyzed by E-NTPDases and ecto-5'nucleotidase, which present the functions of removing ATP and generating adenosine. In this study, we evaluated ATP, ADP, and AMP hydrolysis in synaptosomes from spinal cord and cerebral cortex of rats at postnatal day 16 after repeated morphine exposure in early life (postnatal day 8 to 14). Additionally, we evaluated E-NTPDase (1, 2 and 3) and ecto-5'nucleotidase gene expression by semi-quantitative RT-PCR analysis. We observed an increase in ATP hydrolysis in the cerebral cortex, and a decrease in ADP hydrolysis in spinal cord. Expression levels of E-NTPDase 1 decreased in cerebral cortex and increased in spinal cord. Our findings highlight the importance of the purinergic system in young rats submitted to repeated morphine exposure by showing that in the neonatal period such exposure is capable of affecting the control system for nucleotide levels, which can promote changes in modulation or transmission of painful stimuli.
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Affiliation(s)
- Joanna Ripoll Rozisky
- Laboratório de Farmacologia da Dor e da Inflamação, Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite, 500 sala 202, CEP 90050-170, Porto Alegre, Brazil
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da Silveira VG, de Paula Cognato G, Müller AP, Figueiró F, Bonan CD, Perry MLS, Battastini AMO. Effect of ketogenic diet on nucleotide hydrolysis and hepatic enzymes in blood serum of rats in a lithium-pilocarpine-induced status epilepticus. Metab Brain Dis 2010; 25:211-7. [PMID: 20443057 DOI: 10.1007/s11011-010-9198-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 02/03/2010] [Indexed: 10/19/2022]
Abstract
The ketogenic diet (KD) is a high-fat and low-carbohydrate diet, used for treating refractory epilepsy in children. We have previously shown alterations in nucleotidase activities from the central nervous system and blood serum of rats submitted to different models of epilepsy. In this study we investigated the effect of KD on nucleotidase activities in the blood serum, as well if KD has any influence in the activity of liver enzymes such as alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase activities in Wistar rats submitted to the lithium-pilocarpine model of epilepsy. At 21 days of age, rats received an injection of lithium chloride and, 18-19 h later, they received an injection of pilocarpine hydrochloride for status epilepticus induction. The results reported herein show that seizures induced by lithium-pilocarpine elicit a significant increase in ATP hydrolysis and alkaline phosphatase activity, as well as a decrease in ADP hydrolysis and aspartate aminotransferase activity. The KD is a rigorous regimen that can be associated with hepatic damage, as shown herein by the elevated activities of liver enzymes and 5'-nucleotidase in blood serum. Further studies are necessary to investigate the mechanism of inhibition of lithium on nucleotidases in blood serum.
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Affiliation(s)
- Vanessa Gass da Silveira
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Anexo, Porto Alegre, Brazil
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Schmidt AP, Böhmer AE, Antunes C, Schallenberger C, Porciúncula LO, Elisabetsky E, Lara DR, Souza DO. Anti-nociceptive properties of the xanthine oxidase inhibitor allopurinol in mice: role of A1 adenosine receptors. Br J Pharmacol 2009; 156:163-72. [PMID: 19133997 PMCID: PMC2697763 DOI: 10.1111/j.1476-5381.2008.00025.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 07/25/2008] [Accepted: 09/02/2008] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Allopurinol is a potent inhibitor of the enzyme xanthine oxidase, used primarily in the treatment of hyperuricemia and gout. It is well known that purines exert multiple effects on pain transmission. We hypothesized that the inhibition of xanthine oxidase by allopurinol, thereby reducing purine degradation, could be a valid strategy to enhance purinergic activity. The aim of this study was to investigate the anti-nociceptive profile of allopurinol on chemical and thermal pain models in mice. EXPERIMENTAL APPROACH Mice received an intraperitoneal (i.p.) injection of vehicle (Tween 10%) or allopurinol (10-400 mg kg(-1)). Anti-nociceptive effects were measured with intraplantar capsaicin, intraplantar glutamate, tail-flick or hot-plate tests. KEY RESULTS Allopurinol presented dose-dependent anti-nociceptive effects in all models. The opioid antagonist naloxone did not affect these anti-nociceptive effects. The non-selective adenosine-receptor antagonist caffeine and the selective A(1) adenosine-receptor antagonist, DPCPX, but not the selective A(2A) adenosine-receptor antagonist, SCH58261, completely prevented allopurinol-induced anti-nociception. No obvious motor deficits were produced by allopurinol, at doses up to 200 mg kg(-1). Allopurinol also caused an increase in cerebrospinal fluid levels of purines, including the nucleosides adenosine and guanosine, and decreased cerebrospinal fluid concentration of uric acid. CONCLUSIONS AND IMPLICATIONS Allopurinol-induced anti-nociception may be related to adenosine accumulation. Allopurinol is an old and extensively used compound and seems to be well tolerated with no obvious central nervous system toxic effects at high doses. This drug may be useful to treat pain syndromes in humans.
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Affiliation(s)
- A P Schmidt
- Department of Biochemistry, ICBS, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Schetinger MRC, Morsch VM, Bonan CD, Wyse ATS. NTPDase and 5'-nucleotidase activities in physiological and disease conditions: new perspectives for human health. Biofactors 2007; 31:77-98. [PMID: 18806312 DOI: 10.1002/biof.5520310205] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Extracellular nucleotides and nucleosides act as signaling molecules involved in a wide spectrum of biological effects. Their levels are controlled by a complex cell surface-located group of enzymes called ectonucleotidases. There are four major families of ectonucleotidases, nucleoside triphosphate diphosphohydrolases (NTPDases/CD39), ectonucleotide pyrophosphatase/phosphodiesterases (E-NPPs), alkaline phosphatases and ecto-5'-nucleotidase. In the last few years, substantial progress has been made toward the molecular identification of members of the ectonucleotidase families and their enzyme structures and functions. In this review, there is an emphasis on the involvement of NTPDase and 5'-nucleotidase activities in disease processes in several tissues and cell types. Brief background information is given about the general characteristics of these enzymes, followed by a discussion of their roles in thromboregulatory events in diabetes, hypertension, hypercholesterolemia and cancer, as well as in pathological conditions where platelets are less responsive, such as in chronic renal failure. In addition, immunomodulation and cell-cell interactions involving these enzymes are considered, as well as ATP and ADP hydrolysis under different clinical conditions related with alterations in the immune system, such as acute lymphoblastic leukemia (ALL), B-chronic lymphocytic leukemia (B-CLL) and infections associated with human immunodeficiency virus (HIV). Finally, changes in ATP, ADP and AMP hydrolysis induced by inborn errors of metabolism, seizures and epilepsy are discussed in order to highlight the importance of these enzymes in the control of neuronal activity in pathological conditions. Despite advances made toward understanding the molecular structure of ectonucleotidases, much more investigation will be necessary to entirely grasp their role in physiological and pathological conditions.
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Affiliation(s)
- Maria Rosa C Schetinger
- Laboratório de Enzimologia Toxicológica, Departamento de Química, CCNE, Universidade Federal de Santa Maria, Avenida Roraima, no 1000, Cidade Universitária, Bairro Camobi, Santa Maria-RS, 97105-900, Brazil.
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