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1.
Gen Physiol Biophys ; 36(1): 83-90, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27901472

RESUMO

We evaluated the effects of low dose deprenyl (LDD, 0.0025 mg/kg per day) and high dose deprenyl (HDD, 0.25 mg/kg per day) treatment of male Wistar rats for 30 days on the activities of SOD and CAT in the cortex, striatum, and hippocampus. Total SOD and MnSOD activities were increased with LDD (p <0.05) in the cortex (0.74 ± 0.03; 0.31 ± 0.02), striatum (0.75 ± 0.02; 0.27 ± 0.03) and CA1 region of the hippocampus (0.75 ± 0.02; 0.29 ± 0.03) compared to the control (0.53 ± 0.02; 0.15 ± 0.02), but reduced (p <0.05) with HDD compared to the LDD group. CAT activity was increased (p <0.05) with LDD in the cortex (27.34 ± 3.11), striatum (22.22 ± 1.85), and hippocampal CA1 region (16.62 ± 2.15) compared to control (10.33 ± 1.01), while a decrease was induced by HDD in the striatum (9.85 ± 1.09) compared to LDD. There was a significant (p <0.05) difference in number of Fluoro Jade B positive CA1 neurons induced by LDD (21.14 ± 2.85%) and HDD (12.61 ± 1.42%), as well as the number of NeuN positive CA1 neurons after LDD (183.35 ± 11.14 cells/mm) and HDD (238.45 ± 14.11 cells/mm (p < 0.05). Deprenyl showed a potential in improving the neurological outcome and reducing the oxidative damage.


Assuntos
Antioxidantes/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Catalase/metabolismo , Selegilina/farmacologia , Superóxido Dismutase/metabolismo , Animais , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Inibidores da Monoaminoxidase/farmacologia , Ratos , Ratos Wistar , Distribuição Tecidual
2.
Metab Brain Dis ; 31(6): 1391-1403, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27393013

RESUMO

Pyramidal cells in the CA1 brain region exhibit an ischemic tolerance after delayed postconditioning; therefore, this approach seems to be a promising neuroprotective procedure in cerebral postischemic injury improvement. However, little is known about the effect of postconditioning on protein expression patterns in the brain, especially in the affected hippocampal neurons after global cerebral ischemia. This study is focused on the examination of the ischemia-vulnerable CA1 neuronal layer and on the acquisition of protection from delayed neuronal death after ischemia. Ischemic-reperfusion injury was induced in Wistar rats and bradykinin was applied 2 days after the ischemic insult in an attempt to overcome delayed cell death. Analysis of complex peptide CA1 samples was performed by automated two dimensional liquid chromatography (2D-LC) fractionation coupled to tandem matrix assisted laser desorption/ionization time-of-flight (MALDI TOF/TOF) mass spectrometry instrumentation. We devoted our attention to differences in protein expression mapping in ischemic injured CA1 neurons in comparison with equally affected neurons, but with bradykinin application. Proteomic analysis identified several proteins occurring only after postconditioning and control, which could have a potentially neuroprotective influence on ischemic injured neurons. Among them, the prominent position occupies a regulator of glutamate level aspartate transaminase AATC, a scavenger of glutamate in brain neuroprotection after ischemia-reperfusion. We identified this enzyme in controls and after postconditioning, but AATC presence was not detected in the ischemic injured CA1 region. This finding was confirmed by two-dimensional differential electrophoresis followed by MALDI-TOF/TOF MS identification. Results suggest that bradykinin as delayed postconditioning may be associated with modulation of protein expression after ischemic injury and thus this procedure can be involved in neuroprotective metabolic pathways.


Assuntos
Bradicinina/administração & dosagem , Isquemia Encefálica/enzimologia , Isquemia Encefálica/prevenção & controle , Região CA1 Hipocampal/enzimologia , Pós-Condicionamento Isquêmico/métodos , Proteômica/métodos , Animais , Isquemia Encefálica/patologia , Região CA1 Hipocampal/patologia , Regulação Enzimológica da Expressão Gênica , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Fatores de Tempo
3.
Folia Biol (Krakow) ; 64(2): 97-103, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29537191

RESUMO

Trimethyltin (TMT) is a toxic substance formerly used as a catalyst in the production of organic substances, as well as in industry and agriculture. TMT poisoning has caused death or severe injury in many dozens of people. The toxicity of TMT is mediated by dose dependent selective damage to the limbic system in humans and other animals, specifically the degeneration of CA1 neurons in the hippocampus. The typical symptoms include memory loss and decreased learning ability. Using knowledge gained in previous studies of global ischaemia, we used delayed postconditioning after TMT intoxication (8 mg/kg i.p.), consisting of applying a stressor (BR, bradykinin 150 µg/kg i.p.) 24 or 48 hours after the injection of TMT. We found that BR had preventive effects on neurodegenerative changes as well as learning and memory deficits induced by TMT intoxication.


Assuntos
Bradicinina/farmacologia , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Compostos de Trimetilestanho/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Cognição , Masculino , Aprendizagem em Labirinto , Memória , Ratos
4.
Neurochem Res ; 40(8): 1728-38, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26216051

RESUMO

Brain damage caused by ischemia or toxic agents leads in selectively vulnerable regions to apoptosis-like delayed neuronal death and can result in irreversible damage. Selectively vulnerable neurons of the CA1 area of hippocampus are particularly sensitive to ischemic damage. We investigated the effects of bradykinin (BR) postconditioning on cerebral ischemic and toxic injury. Transient forebrain ischemia was induced by four-vessel occlusion for 10 min and toxic injury was induced by trimethyltin (TMT, 8 µg/kg i.p.). BR as a postconditioner at a dose of 150 µg/kg was applied intraperitoneally 48 h after ischemia or TMT intoxication. Experimental animals were divided into groups according to the length of survival (short-3 and 7 days, and long-28 days survival) and according to the applied ischemic or toxic injury. Glutamate concentration was lowered in both CA1 and dentate gyrus areas of hippocampus after the application of BR postconditioning in both ischemic and toxic brain damage. The number of degenerated neurons in the hippocampal CA1 region was significantly lower in BR-treated ischemic and toxic groups compared to vehicle group. The behavioral test used in our experiments confirms also the memory improvement in conditioned animals. The rats' ability to form spatial maps and learn was preserved, which is visible from our Barnes maze results. By using the methods of delayed postconditioning is possible to stimulate the endogenous protective mechanisms of the organism and induce the neuroprotective effect. In this study we demonstrated that BR postconditioning, if applied before the onset of irreversible neurodegenerative changes, induced neuroprotection against ischemic or toxic injury.


Assuntos
Bradicinina/uso terapêutico , Isquemia Encefálica/tratamento farmacológico , Hipóxia Encefálica/tratamento farmacológico , Pós-Condicionamento Isquêmico/métodos , Fármacos Neuroprotetores/uso terapêutico , Animais , Bradicinina/farmacologia , Isquemia Encefálica/metabolismo , Hipóxia Encefálica/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Wistar
5.
Gen Physiol Biophys ; 33(4): 403-10, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25032511

RESUMO

Induction of ischemic tolerance (IT), the ability of an organism to survive an otherwise lethal ischemia, is the most effective known approach to preventing postischemic damage. IT can be induced by exposing animals to a broad range of stimuli. In this study we tried to induce IT of brain neurons using ionizing radiation (IR). A preconditioning (pre-C) dose of 10, 20, 30 or 50 Gy of gamma rays was used 2 days before an 8 min ischemia in adult male rats. Ischemia alone caused the degeneration of almost one half of neurons in CA1 region of hippocampus. However, a significant decrease of the number of degenerating neurons was observed after higher doses of radiation (30 and 50 Gy). Moreover, ischemia significantly impaired the spatial memory of rats as tested in Morris's water maze. In rats with a 50 Gy pre-C dose, the latency times were reduced to values close to the control level. Our study is the first to reveal that IR applied in sufficient doses can induce IT and thus allow pyramidal CA1 neurons to survive ischemia. In addition, we show that the beneficial effect of IR pre-C is proportional to the radiation dose.


Assuntos
Ataque Isquêmico Transitório/terapia , Precondicionamento Isquêmico/métodos , Radiação Ionizante , Animais , Ataque Isquêmico Transitório/fisiopatologia , Masculino , Tolerância a Radiação/efeitos da radiação , Ratos , Ratos Wistar , Aprendizagem Espacial/efeitos da radiação
6.
Gen Physiol Biophys ; 32(1): 139-42, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23531843

RESUMO

We monitored possible influence of transient focal and global brain ischemia on BDNF blood level. In both models noticeable fluctuation of BDNF concentration mainly in reperfusion was observed. During the first 90 min, BDNF in total blood and in blood cells continuously decreased in both models but plasma BDNF raised at 40 min and peaked at 90 min of reperfusion. Our data confirm the impact of transient brain ischemia on BDNF levels in the circulatory system, suggest blood cells as a possible source of BDNF and demonstrate the interdependence of blood compartments and physiological state of an affected organism.


Assuntos
Isquemia Encefálica/sangue , Fator Neurotrófico Derivado do Encéfalo/sangue , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Isquemia Encefálica/fisiopatologia , Infarto da Artéria Cerebral Média/patologia , Masculino , Neurônios/metabolismo , Ratos , Ratos Wistar , Reperfusão , Traumatismo por Reperfusão , Espectrofotometria/métodos , Fatores de Tempo
7.
Neurochem Res ; 37(10): 2085-91, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22711336

RESUMO

Ischemic tolerance based on the synthesis of protective proteins acquires its full strength by repeated exposure to stress, and "the end effector of tolerance" may paradoxically be activated by the second or lethal stress, particularly in the case of preconditioning. That happens when an additional nonspecific stressor is applied either before (preconditioning) or after (postconditioning) the period of lethal ischemia. A combination of antioxidants with pre or postconditioning prevents the acquisition of tolerance, and in the case of more severe attacks repeated stress can lead to accumulation of damage. Our attempt to weaken ischemic injury to hippocampal CA1 with antioxidants applied after lethal stress, i.e. before delayed postconditioning, was ineffective. We then tried using rapid postconditioning consisting of 30-s reperfusion alternating with 15-s ischemia repeated three times and applied immediately at the end of lethal ischemia as a tool decreasing post-ischemic production of reactive oxygen species, and combining that with delayed postconditioning consisting of an i.p. injection of Bradykinin 2 days after lethal ischemia. This approach once more confirmed the efficacy of both rapid as well as delayed postconditioning but, more importantly, it demonstrated the possibility of effectively combining these two procedures. Our findings further confirm that in cases of delayed neuronal death, which is practically pathologically-induced apoptosis, there exists a 2-day-wide therapeutic window that can be effectively exploited.


Assuntos
Isquemia Encefálica/terapia , Animais , Antioxidantes/farmacologia , Bradicinina/administração & dosagem , Isquemia Encefálica/patologia , Ensaio de Imunoadsorção Enzimática , Imuno-Histoquímica , Masculino , Ratos , Ratos Wistar , Reperfusão
8.
Neurochem Res ; 36(3): 476-86, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21203836

RESUMO

The effects of a selective inducible nitric oxide synthase inhibitor aminoguanidine (AG) on neuronal cells survival in hippocampal CA1 region after middle cerebral artery occlusion (MCAO) were examined. Transient focal cerebral ischemia was induced in rats by 60 or 90 min of MCAO, followed by 7 days of reperfusion. AG treatment (150 mg/kg i.p.) significantly reduced total infarct volumes: by 70% after 90 min MCAO and by 95% after 60 min MCAO, compared with saline-treated ischemic group. The number of degenerating neurons in hippocampal CA1 region was also markedly lower in aminoguanidine-treated ischemic groups compared to ischemic groups without AG-treatment. The number of iNOS-positive cells significantly increased in the hippocampal CA1 region of ischemic animals, whereas it was reduced in AG-treated rats. Our findings demonstrate that aminoguanidine decreases ischemic brain damage and improves neurological recovery after transient focal ischemia induced by MCAO.


Assuntos
Inibidores Enzimáticos/farmacologia , Guanidinas/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Infarto da Artéria Cerebral Média/patologia , Ataque Isquêmico Transitório/patologia , Animais , Hipocampo/citologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Degeneração Neural/patologia , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/patologia , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Ratos , Ratos Wistar
9.
Gen Physiol Biophys ; 29(2): 113-21, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20577022

RESUMO

Although ischemia/reperfusion injury remains incompletely understood, it appears that reactive oxygen species produced mainly during postischemic recirculation play a critical role. The present study examined the impact of forebrain ischemia and subsequent one-day reperfusion on several blood parameters. We determined glutamate concentration in whole blood, measured Cu/Zn- and Mn-SOD (superoxide dismutase) activity in blood cells as well as plasma, and investigated the prevalence of single and double strand breaks of lymphocyte DNA. The results of our experiment showed that the concentration of glutamic acid in whole blood was increased by about 25%. Antioxidant activity of total SOD and Cu/Zn-SOD was reduced in blood cells and plasma. Mn-SOD activity in blood cells was not affected by ischemic insult and one-day reperfusion, but we detected its significantly lower activity in samples of plasma. We observed a weakly reduced level of double and a significantly elevated level of single strand breaks of lymphocyte DNA. In conclusion, one day of recovery after the ischemic attack failed to return peripheral circulatory system to physiological conditions. Reduced antioxidant capacity in the blood and an elevated level of excitotoxic amino acid glutamate may cause lymphocyte DNA damage, and probably contribute to insufficient postischemic recovery of brain tissue.


Assuntos
Isquemia Encefálica/fisiopatologia , Prosencéfalo/irrigação sanguínea , Prosencéfalo/lesões , Traumatismo por Reperfusão/fisiopatologia , Animais , Isquemia Encefálica/sangue , Circulação Cerebrovascular/fisiologia , Dano ao DNA , Ácido Glutâmico/sangue , Linfócitos/metabolismo , Masculino , Ratos , Ratos Wistar , Traumatismo por Reperfusão/sangue , Superóxido Dismutase/sangue
10.
Cell Mol Neurobiol ; 29(6-7): 887-94, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19259803

RESUMO

AIMS: Brain ischemia-reperfusion injury remains incompletely understood but appears to involve a complex series of interrelated biochemical pathways caused mainly by a burst of reactive oxygen species (ROS). In the present work we studied the impact of postischemic condition in the early phase of reperfusion on plasma and blood cells. METHODS: Transient forebrain ischemia was induced in Wistar rats by four-vessel occlusion model. Blood samples collected during postischemic reperfusion 20, 40, 60, 90, and 120 min after ischemia were used for assessing breaks of lymphocyte DNA, fluorimetric measurement of whole blood glutamate concentration, and spectrophotometrical determination of SOD activity in plasma and blood cells. RESULTS: Our results showed the most interesting changes of all observed parameters mainly at 40 and 120 min of reperfusion, when we observed peak DNA damage of lymphocytes and highest glutamate level and total and Cu/Zn SOD activity. At those time points, Mn SOD activity was low in plasma, as well as in blood cells. On the contrary, at 60 and 90 min, all studied parameters were approximately at the level of control. CONCLUSION: Ischemia/reperfusion injury has influence on blood cells and has at least two waves of impact on DNA damage of peripheral lymphocytes, affects activity of major antioxidant enzymes SODs, as well as blood glutamic acid level. Elevation of Mn SOD activity probably plays an important role in the processes of elimination of postischemic damage in blood cells.


Assuntos
Dano ao DNA , Ácido Glutâmico/sangue , Linfócitos/metabolismo , Superóxido Dismutase/metabolismo , Animais , Ataque Isquêmico Transitório/sangue , Masculino , Prosencéfalo/irrigação sanguínea , Ratos , Ratos Wistar , Traumatismo por Reperfusão/sangue , Superóxido Dismutase/sangue
11.
Cell Mol Neurobiol ; 29(6-7): 837-44, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19259806

RESUMO

Ischemic postconditioning is a very effective way how to prevent delayed neuronal death. Effect of Ginkgo biloba extract (EGb 761; 40 mg/kg) posttreatment was studied on the rat model of transient forebrain ischemia and ischemia/postconditioning. Global ischemia was produced by four-vessel occlusion in Wistar male rats. Two experimental protocols were used: (a) 10 min of ischemia/7 days of reperfusion with or without EGb 761 treatment or (b) 10 min of ischemia/2 days of reperfusion/5 min of ischemia (postconditioning), following 5 days of reperfusion. EGb 761 was applied as follows: 30 min before 10 min of ischemia then 5 h, 1 and 2 days after 10 min of ischemia. Fluoro Jade B, marker for neuronal degeneration, was used for quantitative analysis of the most vulnerable hippocampal CA1 neurons. Cognitive and memory functions were tested by Morris water maze, as well. Administration of EGb 761 30 min before 10 min of ischemia or 5 h after ischemia has rather no protective effect on neuronal survival in CA1 region. Ten minutes of ischemia following ischemic postconditioning after 2 days of reperfusion trigger a significant neuroprotection of CA1 neurons, but it is abolished by EGb 761 posttreatment. Ischemia/postconditioning group showed a significant improvement of learning and memory on the seventh day of reperfusion. Protection of the most vulnerable CA1 neurons after ischemia/postconditioning is abolished by exogenous antioxidant treatment used in different time intervals after initial ischemia. Moreover, combination of EGb 761 administration with repeated stress (5 min ischemia used as postconditioning) causes cumulative injury of CA1 neurons.


Assuntos
Antioxidantes/farmacologia , Hipocampo/patologia , Ataque Isquêmico Transitório/fisiopatologia , Degeneração Neural/fisiopatologia , Animais , Morte Celular/efeitos dos fármacos , Fluoresceínas , Ginkgo biloba , Hipocampo/efeitos dos fármacos , Ataque Isquêmico Transitório/complicações , Ataque Isquêmico Transitório/patologia , Masculino , Aprendizagem em Labirinto , Degeneração Neural/tratamento farmacológico , Degeneração Neural/etiologia , Degeneração Neural/patologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Compostos Orgânicos , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar
12.
Cell Mol Neurobiol ; 29(6-7): 991-8, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19291391

RESUMO

Short term sublethal ischemia or ischemic preconditioning gives protection to the neurons against subsequent lethal ischemic attack. This so-called ischemic tolerance can also be provided by certain drugs. We examined the effect of noradrenalin and EGb 761 on the spinal cord neurons injured by 30 min occlusion of abdominal aorta in rabbits. The animals survived 48 and 72 h. Degenerated neurons were visualized by Fluoro Jade B method, viable neurons were demonstrated immunohistochemically with NeuN and ubiquitin antibodies. The rabbits with noradrenalin administration 48 h before 30 min of ischemia and 48/72 h of reperfusion, showed significant increase of degenerated Fluoro Jade B labeled neurons. Animals of both groups were paraplegic. Rabbits pretreated 7 days with EGb 761 prior to 30 min of ischemia and with 48/72 h of reperfusion revealed significant decrease of Fluoro Jade B-positive neurons when compared with the groups with 30 min of ischemia followed by 48/72 h of reperfusion. In the NeuN sections, the number of viable neurons was moderately decreased. These animals showed no paraplegia. Ubiquitin aggregates occurred in the cytoplasm of degenerated neurons in the sections of rabbits preconditioned with noradrenalin 48 h prior to 30 min of ischemia and followed by 48 h of reperfusion while after 72 h of reperfusion, shrunk light shadows without ubiquitin reaction were visible. Our results indicate that EGb 761 could be involved in protection of spinal cord neurons against ischemic injury while effect of noradrenalin is not unambiguous.


Assuntos
Isquemia/tratamento farmacológico , Norepinefrina/uso terapêutico , Extratos Vegetais/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Contagem de Células , Fluoresceínas , Ginkgo biloba , Imuno-Histoquímica , Isquemia/patologia , Masculino , Neurônios/patologia , Compostos Orgânicos , Coelhos , Traumatismo por Reperfusão/patologia , Medula Espinal/irrigação sanguínea , Medula Espinal/patologia
13.
Cell Mol Neurobiol ; 29(6-7): 871-8, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19259804

RESUMO

AIMS: The present study was undertaken to evaluate possible neuroprotective effect of bradykinin against delayed neuronal death in hippocampal CA1 neurons if applied two days after transient forebrain ischemia in the rat. METHODS: Transient forebrain ischemia was induced in male Wistar rats by four-vessel occlusion for 8 min. To assess efficacy of bradykinin as a new stressor for delayed postconditioning we used two experimental groups of animals: ischemia 8 min and 3 days of survival, and ischemia 8 min and 3 days of survival with i.p. injection of bradykinin (150 microg/kg) applied 48 h after ischemia. RESULTS: We found extensive neuronal degeneration in the CA1 region at day 3 after ischemia/reperfusion. The postischemic neurodegeneration was preceded by increased activity of mitochondrial enzyme MnSOD in cytoplasm, indicating release of MnSOD from mitochondria in the process of delayed neuronal death. Increased cytosolic cytochrome c and subsequently caspase-3 activation are additional signs of neuronal death via the mitochondrial pathway. Bradykinin administration significantly attenuated ischemia-induced neuronal death, and also suppressed the release of MnSOD, and cytochrome c, and prevented caspase-3 activation. CONCLUSIONS: Bradykinin can be used as an effective stressor able to prevent mitochondrial failure leading to apoptosis-like delayed neuronal death in postischemic rat hippocampus.


Assuntos
Bradicinina/uso terapêutico , Hipocampo/enzimologia , Hipocampo/patologia , Ataque Isquêmico Transitório/patologia , Degeneração Neural/patologia , Neurônios/enzimologia , Animais , Apoptose/fisiologia , Encéfalo/irrigação sanguínea , Encéfalo/enzimologia , Encéfalo/patologia , Caspase 3/metabolismo , Contagem de Células , Morte Celular/efeitos dos fármacos , Citocromos c/metabolismo , Imuno-Histoquímica , Ataque Isquêmico Transitório/complicações , Masculino , Degeneração Neural/etiologia , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
14.
Cell Mol Neurobiol ; 29(6-7): 821-5, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19259808

RESUMO

The aim of this study was to validate the ability of postconditioning, used 2 days after kainate intoxication, to protect selectively vulnerable hippocampal CA1 neurons against delayed neuronal death. Kainic acid (8 mg/kg, i.p.) was used to induce neurodegeneration of pyramidal CA1 neurons in rat hippocampus. Fluoro Jade B, the specific marker of neurodegeneration, and NeuN, a specific neuronal marker were used for visualization of changes 7 days after intoxication without and with delayed postconditioning (norepinephrine, 3.1 mumol/kg i.p., 2 days after kainate administration) and anticonditioning (Extract of Ginkgo biloba, 40 mg/kg p.o used simultaneously with kainate). Morris water maze was used on 6th and 7th day after kainate to test learning and memory capabilities of animals. Our results confirm that postconditioning if used at right time and with optimal intensity is able to prevent delayed neuronal death initiated not only by ischemia but kainate intoxication, too. The protective effect of repeated stress-postconditioning was suppressed if extract of Ginkgo biloba (EGb 761, 40 mg/kg p.o.) has been administered together with kainic acid. It seems that combination of lethal stress and antioxidant treatment blocks the activation of endogenous protecting mechanism known as ischemic tolerance, aggravates neurodegeneration and, after repeated stress is able to cause cumulative damage. This observation could be very valuable in situation when the aim of treatment is elimination of unwanted cell population from the organism.


Assuntos
Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Hipocampo/patologia , Degeneração Neural/induzido quimicamente , Animais , Contagem de Células , Fluoresceínas , Ginkgo biloba , Hipocampo/efeitos dos fármacos , Imuno-Histoquímica , Ácido Caínico/toxicidade , Aprendizagem em Labirinto , Neurônios/efeitos dos fármacos , Norepinefrina/farmacologia , Compostos Orgânicos , Extratos Vegetais/farmacologia , Ratos
15.
Gen Physiol Biophys ; 28(3): 242-8, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20037189

RESUMO

The purpose of this study was to investigate effects of carnitine administration on protein synthesis recovery after transient cerebral ischemia. Rats received L-carnitine in two doses of 16 mmol/kg i.p. 15 min before ischemia and just on the onset of reperfusion. Transient forebrain ischemia was induced by 4-vessel occlusion for 15 min, followed by 30 min or 7 days of reperfusion. Protein synthesis rate, reinitiation ability and neurodegeneration in the frontal cortex and hippocampus were measured by the incorporation of radioactively labelled leucine into polypeptide chains in postmitochondrial supernatants and by Fluoro-Jade B staining. A protective effect was observed, on protein synthesis as well as the number of surviving neurons, in the L-carnitine-treated groups. Our results indicate that L-carnitine can exert a protective effect in the development of reperfusion-induced injury. L-carnitine significantly reduced the ischemia/reperfusion-induced inhibition of translation and neurodegeneration in the neocortex as well as in the highly sensitive hippocampus and dorsolateral striatum. We expect that the ability of L-carnitine to keep translational machinery on facilitates efficacy of postischemic remodulation of gene expression.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Carnitina/farmacologia , Fármacos Neuroprotetores/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Carnitina/administração & dosagem , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Degeneração Neural/tratamento farmacológico , Degeneração Neural/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Fatores de Tempo
16.
J Neurol Sci ; 253(1-2): 61-5, 2007 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-17215005

RESUMO

The activity of SOD and CAT was measured in controls and 5 h after 5, 10 and 15 min of ischemia, as well as 1 or 2 days after 10 min of ischemia in the hippocampus and in the CSF. A significant increase in total SOD activity 5 h after ischemia was caused mainly by increased CuZn-SOD activity. The highest values were measured 5 h after 5 min ischemia (by 160%) and smallest if 15 min (by 40%) of ischemia was used. In comparison to the hippocampus, the activity of SOD in CSF increased equally after all intervals of ischemia. Activities of total SOD and CuZn-SOD after 10 min of ischemia in the hippocampus were significantly increased only after 5 and 24 h of reperfusion but in CSF they were increased after all examined intervals of reperfusion. The activity of CAT was significantly increased in the hippocampus after 5 (by 260%), 10 and 15 min (by 100%) of ischemia. CAT activity in CSF was increased equally after all intervals of ischemia (by 200%). Ischemic attack causes a rapid response in hippocampal tissue as well as in the CSF, represented by an increase in the activity of endogenous antioxidant enzymes SOD and CAT.


Assuntos
Catalase/líquido cefalorraquidiano , Hipocampo/enzimologia , Ataque Isquêmico Transitório/metabolismo , Superóxido Dismutase/líquido cefalorraquidiano , Animais , Antioxidantes/metabolismo , Masculino , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
17.
Neurosci Lett ; 393(2-3): 249-54, 2006 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-16289321

RESUMO

In asphyxiated newborns iron, released from heme and ferritin and deposited in the brain, contributes to neurodegeneration. Because hypothermia provides neuroprotection, newborn mammals, showing spontaneously reduced body temperature, might avoid the iron-mediated neurotoxicity. Therefore, we decided to study the effects of body temperature and chelation of iron with deferoxamine on iron accumulation in the brain of three weeks old rats exposed neonatally to a critical anoxia. At the age of two days, newborn rats were exposed to anoxia in 100% nitrogen atmosphere. Rectal temperature was kept at 33 degrees C (typical of the rat neonates), or elevated to a level typical of febrile (39 degrees C) adults. Control rats were exposed to atmospheric air in the respective thermal conditions. Half of the rats exposed to anoxia under hyperthermic conditions were injected with deferoxamine (DF), immediately after anoxia and 24 h later. Regional changes in cerebral iron deposition were examined in the frontal cortex, the hippocampus and the striatum, using iron histochemistry, when the rats reached the age of three weeks. Increased iron staining was found in neurons of each of the three cerebral regions in rats exposed to neonatal anoxia under hyperthermic conditions and the iron accumulation was prevented by postanoxic DF injection. In conclusion, febrile body temperature amplifies cerebral hyperferremia, which might induce neurodegenerative disturbances in the brain. On the other hand, a protection against the brain hyperferremia can be achieved by both the reduced physiological neonatal body temperature and by postasphyxic DF administration.


Assuntos
Temperatura Corporal/fisiologia , Encéfalo/metabolismo , Hipóxia/metabolismo , Ferro/metabolismo , 3,3'-Diaminobenzidina , Análise de Variância , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Contagem de Células/métodos , Desferroxamina/administração & dosagem , Hipóxia/terapia , Ferro/toxicidade , Ratos , Ratos Wistar , Sideróforos/administração & dosagem
18.
Neural Regen Res ; 11(6): 865-74, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27482198

RESUMO

Ischemia as a serious neurodegenerative disorder causes together with reperfusion injury many changes in nervous tissue. Most of the neuronal damage is caused by complex of biochemical reactions and substantial processes, such as protein agregation, reactions of free radicals, insufficient blood supply, glutamate excitotoxicity, and oxidative stress. The result of these processes can be apoptotic or necrotic cell death and it can lead to an irreversible damage. Therefore, neuroprotection and prevention of the neurodegeneration are highly important topics to study. There are several approaches to prevent the ischemic damage. Use of many modern therapeutical methods and the incorporation of several substances into the diet of patients is possible to stimulate the endogenous protective mechanisms and improve the life quality.

19.
Eur J Pharmacol ; 788: 21-28, 2016 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-27292162

RESUMO

The aim of the study was to investigate the effect of R-(-)-deprenyl administration on the activity and localization of superoxide dismutases (SODs) and catalase (CAT) in rat testis. After 30 days of intraperitoneal administration of either saline (control) or R-(-)-deprenyl dissolved in saline at concentrations of 0.0025mg/kg (low dose of deprenyl, LDD) or 0.25mg/kg (high dose of deprenyl, HDD), males were killed by thiopental, and their testes were collected. We found that deprenyl administration significantly increased the activity of antioxidant enzymes, and this effect varied by dosage. LDD caused significant elevation of all monitored enzymes, but HDD did not increase the activity of SOD2. Employing immunohistochemistry, we detected enzymes predominantly in Leydig cells (SOD1, SOD2, CAT), in late spermatids and residual bodies (SOD1, SOD2), and in primary spermatocytes (SOD2). Histopathological examination did not reveal testicular damage in experimental groups compared to control. Deprenyl proved to be a potent stimulator of antioxidant enzymes in rat testes; therefore, it could be used in the therapy of male infertility. On the other hand, it is crucial to choose a proper dose, since lower dose was more competent compared to a dosage that was one hundred times higher.


Assuntos
Antioxidantes/metabolismo , Catalase/metabolismo , Selegilina/administração & dosagem , Selegilina/farmacologia , Superóxido Dismutase/metabolismo , Testículo/efeitos dos fármacos , Testículo/metabolismo , Animais , Masculino , Ratos , Ratos Wistar , Testículo/citologia , Testículo/enzimologia
20.
J Mol Neurosci ; 57(1): 73-82, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25972121

RESUMO

The impact of therapeutic intervention in stroke depends on its appropriate timing during infarct evolution. We have studied markers of brain tissue damage initiated by permanent occlusion of the middle cerebral artery (MCAO) at three time points during which the infarct spread (1, 3 and 6 h). Based on Evans Blue extravasation and immunohistochemical detection of neurons, we confirmed continuous disruption of blood-brain barrier and loss of neurons in the ischaemic hemisphere that peaked at the sixth hour, especially in the core. Glutamate content started to rise dramatically in the entire hemisphere during the first 3 h; the highest level was determined in the core 6 h after MCAO (141 % increase). Moreover, the enzyme antioxidant defence grew by about 42 % since the first hour in the ipsilateral penumbra. Enzymes of the apoptotic pathway as well as mitochondrial enzyme release were detected since the third hour of MCAO in the ischaemic hemisphere; all achieved their maxima in the penumbra during both time periods (except cytochrome C). In conclusion, the preserved integrity of mitochondrial membrane and incompletely developed process of apoptosis may contribute to the better therapeutic outcome after ischaemic attack; however, a whole brain response should not be omitted.


Assuntos
Infarto da Artéria Cerebral Média/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Permeabilidade Capilar , Ácido Glutâmico/metabolismo , Infarto da Artéria Cerebral Média/patologia , Masculino , Ratos , Ratos Wistar
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