RESUMO
Elevated levels of methionine in blood characterize the hypermethioninemia, which may have genetic or non-genetic origin, as for example from high protein diet. Born rats from hypermethioninemic mothers presented cerebral oxidative stress, inhibition of Na+,K+-ATPase, memory deficit and ultrastructure cerebral changes. Melatonin is a hormone involved in circadian rhythm and has antioxidant effects. The aim of this study was to verify the possible neuroprotective effects of melatonin administration in hypermethioninemic pregnant rats on damage to biomolecules (Na+,K+-ATPase, sulfhydryl content and DNA damage index) and behavior (open field, novel object recognition and water maze tasks), as well as its effect on cells morphology by electron microscopy in offspring. Wistar female rats received methionine (2.68⯵mol/g body weight) and/or melatonin (10â¯mg/kg body weight) by subcutaneous injections during entire pregnancy. Control rats received saline. Biochemical analyzes were performed at 21 and 30 days of life of offspring and behavioral analyzes were performed only at 30 days of age in male pups. Results showed that gestational hypermethioninemia diminished Na+,K+-ATPase activity and sulfhydryl content and increased DNA damage at 21 and 30 days of life. Melatonin was able to totally prevent Na+,K+-ATPase activity alteration at 21 days and partially prevent its alteration at 30 days of rats life. Melatonin was unable in to prevent sulfhydryl and DNA damage at two ages. It also improved DNA damage, but not at level of saline animals (controls). Regarding to behavioral tests, data showed that pups exposed to gestational hypermethioninemia decreased reference memory in water maze, spent more time to the center of the open field and did not differentiate the objects in the recognition test. Melatonin was able to prevent the deficit in novel object recognition task. Electron microscopy revealed ultrastructure alterations in neurons of hypermethioninemic at both ages of offspring, whose were prevented by melatonin. These findings suggest that melatonin may be a good neuroprotective to minimize the harmful effects of gestational hypermethioninemia on offspring.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/tratamento farmacológico , Glicina N-Metiltransferase/deficiência , Melatonina/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Complicações na Gravidez/tratamento farmacológico , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Melatonina/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Reconhecimento Psicológico/efeitos dos fármacosRESUMO
Although the use, and misuse, of methylphenidate is increasing in childhood and adolescence, there is little information about the consequences of this psychostimulant chronic use on brain and behavior during development. The aim of the present study was to investigate hippocampus biochemical, histochemical, and behavioral effects of chronic methylphenidate treatment to juvenile rats. Wistar rats received intraperitoneal injections of methylphenidate (2.0 mg/kg) or an equivalent volume of 0.9 % saline solution (controls), once a day, from the 15th to the 45th day of age. Results showed that chronic methylphenidate administration caused loss of astrocytes and neurons in the hippocampus of juvenile rats. BDNF and pTrkB immunocontents and NGF levels were decreased, while TNF-α and IL-6 levels, Iba-1 and caspase 3 cleaved immunocontents (microglia marker and active apoptosis marker, respectively) were increased. ERK and PKCaMII signaling pathways, but not Akt and GSK-3ß, were decreased. SNAP-25 was decreased after methylphenidate treatment, while GAP-43 and synaptophysin were not altered. Both exploratory activity and object recognition memory were impaired by methylphenidate. These findings provide additional evidence that early-life exposure to methylphenidate can have complex effects, as well as provide new basis for understanding of the biochemical and behavioral consequences associated with chronic use of methylphenidate during central nervous system development.
Assuntos
Astrócitos/patologia , Comportamento Animal/efeitos dos fármacos , Hipocampo/patologia , Metilfenidato/toxicidade , Neurônios/patologia , Animais , Antígenos Nucleares/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Citocinas/metabolismo , Comportamento Exploratório/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Modelos Biológicos , Fatores de Crescimento Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Wistar , Reconhecimento Psicológico , Transdução de Sinais , Proteína 25 Associada a Sinaptossoma/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Mild hyperhomocysteinemia is considered to be a risk factor for cerebral and cardiovascular disorders and can be modeled in experimental rats. Inflammation has been implicated in the toxic effects of homocysteine. Cholinergic signaling controls cytokine production and inflammation through the "cholinergic anti-inflammatory pathway," and brain acetylcholinesterase activity plays a role in this regulation. The aim of this present study is to investigate the effect of mild chronic hyperhomocysteinemia on proinflammatory cytokine levels in the brain, heart, and serum of rats. Activity, immunocontent, and gene expression of acetylcholinesterase in the brain and butyrylcholinesterase activity in serum were also evaluated. Mild hyperhomocysteinemia was induced in Wistar rats by homocysteine administration (0.03 µmol/g of body weight) twice a day, from the 30th to the 60th days of life. Controls received saline in the same volumes. Results demonstrated an increase in tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and the chemokine monocyte chemotactic protein-1 (MCP-1) in the hippocampus, as well as an increase in IL-1ß and IL-6 levels in cerebral cortex. Acetylcholinesterase activity was increased in rats subjected to mild hyperhomocysteinemia in both cerebral structures tested; the immunocontent of this enzyme was also increased in the cerebral cortex and decreased in the hippocampus. Levels of acetylcholinesterase mRNA transcripts were not altered. Peripherally, homocysteine increased TNF-α, IL-6, and MCP-1 levels in the heart and IL-6 levels in serum. Taken altogether, these findings suggest that homocysteine promotes an inflammatory status that can contribute, at least in part, to neuronal and cardiovascular dysfunctions observed in mild hyperhomocysteinemia.
Assuntos
Acetilcolinesterase/metabolismo , Córtex Cerebral/metabolismo , Citocinas/metabolismo , Hipocampo/metabolismo , Hiper-Homocisteinemia/metabolismo , Animais , Córtex Cerebral/patologia , Feminino , Hipocampo/patologia , Inflamação/metabolismo , Inflamação/patologia , RNA Mensageiro/metabolismo , Ratos WistarRESUMO
AIM: The effects of physical exercise on oxidative stress parameters and immunocontent of NF-кß/p65 in lung of rats submitted to lung injury, as well as its possible protective effect on the changes in the alveolar-capillary barrier (total cell count, lactate dehydrogenase and total protein) in the bronchoalveolar lavage fluid (BALF) and the inflammatory infiltration in the pulmonary parenchyma were evaluated. MAIN METHODS: Wistar rats were submitted to two months of physical exercise and after this period, lung injury was induced by intratracheal instillation of lipopolysaccharide (dose of 100 µg/100 g body weight). Twelve hours after injury, the animals were sacrificed and lung and BALF were collected. KEY FINDINGS: Results showed an increase in reactive species production, lipid peroxidation, oxidative damage to protein, as well as in nitrite levels and NF-кß/p65 immunocontent in lung of rats submitted to lung injury. Physical exercise was able to totally prevent the increase in reactive species, nitrite levels and NF-кß/p65 immunocontent, but partially prevented the damage to protein. Superoxide dismutase and catalase were not changed in lung injury group, but the activities of these enzymes were increased in lung injury plus exercise group. Non-enzymatic antioxidant capacity, glutathione content and glutathione peroxidase were decreased and exercise totally prevented such effects. Rats subjected to lung injury presented an increase in total cell, lactate dehydrogenase and total protein; exercise partially prevented the increase in lactate dehydrogenase. SIGNIFICANCE: These findings suggest that physical exercise may prevent, at least partially, the oxidative damage caused by experimental lung injury, suggesting that exercise may have an important role as protector in this condition.
Assuntos
Barreira Alveolocapilar/metabolismo , Lesão Pulmonar/metabolismo , Estresse Oxidativo , Condicionamento Físico Animal , Animais , Barreira Alveolocapilar/patologia , Barreira Alveolocapilar/fisiopatologia , Líquido da Lavagem Broncoalveolar , Catalase/metabolismo , L-Lactato Desidrogenase/metabolismo , Lipopolissacarídeos/toxicidade , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/patologia , Lesão Pulmonar/fisiopatologia , Masculino , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Fator de Transcrição RelA/metabolismoRESUMO
The use of psychostimulant methylphenidate has increased in recent years for the treatment of attention-deficit hyperactivity disorder in children and adolescents. However, the behavioral and neurochemical changes promoted by its use are not yet fully understood, particularly when used for a prolonged period during stages of brain development. Thus, the aim of this study was to determine some parameters of oxidative stress in encephalic structures of juvenile rats subjected to chronic methylphenidate treatment. Wistar rats received intraperitoneal injections of methylphenidate (2.0 mg/kg) once a day, from the 15th to the 45th day of age or an equivalent volume of 0.9% saline solution (controls). Two hours after the last injection, animals were euthanized and the encephalic structures obtained for determination of oxidative stress parameters. Results showed that methylphenidate administration increased the activities of superoxide dismutase and catalase, but did not alter the levels of reactive species, thiobarbituric acid reactive substances levels and sulfhydryl group in cerebellum of rats. In striatum and hippocampus, the methylphenidate-treated rats presented a decrease in the levels of reactive species and thiobarbituric acid reactive substances, but did not present changes in the sulfhydryl groups levels. In prefrontal cortex, methylphenidate promoted an increase in reactive species formation, SOD/CAT ratio, and increased the lipid peroxidation and protein damage. These findings suggest that the encephalic structures respond differently to methylphenidate treatment, at least, when administered chronically to young rats. Notably, the prefrontal cortex of juvenile rats showed greater sensitivity to oxidative effects promoted by methylphenidate in relation to other encephalic structures analyzed.
Assuntos
Estimulantes do Sistema Nervoso Central/toxicidade , Metilfenidato/toxicidade , Córtex Pré-Frontal/metabolismo , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Fluoresceínas , Glutationa Peroxidase/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Injeções Intraperitoneais , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo/fisiologia , Córtex Pré-Frontal/patologia , Ratos , Ratos Wistar , Espécies Reativas de Nitrogênio/metabolismo , Compostos de Sulfidrila/metabolismo , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Accumulating evidence indicates that resveratrol potently protects against cerebral ischemia damage due to its oxygen free radicals scavenging and antioxidant properties. However, cellular mechanisms that may underlie the neuroprotective effects of resveratrol in brain ischemia are not fully understood yet. This study aimed to investigate the potential association between the neuroprotective effect of resveratrol and the apoptosis/survival signaling pathways, in particular the glycogen synthase kinase 3 (GSK-3ß) and cAMP response element-binding protein (CREB) through phosphatidylinositol 3-kinase (PI3-K)-dependent pathway. An experimental model of global cerebral ischemia was induced in rats by the four-vessel occlusion method for 10 min and followed by different periods of reperfusion. Nissl staining indicated extensive neuronal death at 7 days after ischemia/reperfusion. Administration of resveratrol by i.p. injections (30 mg/kg) for 7 days before ischemia significantly attenuated neuronal death. Both GSK-3ß and CREB appear to play a critical role in resveratrol neuroprotection through the PI3-K/Akt pathway, as resveratrol pretreatment increased the phosphorylation of Akt, GSK-3ß and CREB in 1 h in the CA1 hippocampus after ischemia/reperfusion. Furthermore, administration of LY294002, an inhibitor of PI3-K, compromised the neuroprotective effect of resveratrol and decreased the level of p-Akt, p-GSK-3ß and p-CREB after ischemic injury. Taken together, the results suggest that resveratrol protects against delayed neuronal death in the hippocampal CA1 by maintaining the pro-survival states of Akt, GSK-3ß and CREB pathways. These data suggest that the neuroprotective effect of resveratrol may be mediated through activation of the PI3-K/Akt signaling pathway, subsequently downregulating expression of GSK-3ß and CREB, thereby leading to prevention of neuronal death after brain ischemia in rats.
Assuntos
Isquemia Encefálica/metabolismo , Região CA1 Hipocampal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Estilbenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/enzimologia , Região CA1 Hipocampal/enzimologia , Região CA1 Hipocampal/metabolismo , Cromonas/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Masculino , Morfolinas/farmacologia , Neurônios/enzimologia , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/metabolismo , Resveratrol , Estilbenos/uso terapêuticoRESUMO
The influence of physical exercise on the effects elicited by homocysteine on glutamate uptake and some parameters of oxidative stress, namely thiobarbituric acid-reactive substances, 2',7'-dichlorofluorescein (H(2)DCF) oxidation, as well as enzymatic antioxidant activities, superoxide dismutase, catalase and glutathione peroxidase in rat cerebral cortex were investigated. Wistar rats received subcutaneous administration of homocysteine or saline (control) from the 6th to 29th day of life. The physical exercise was performed from the 30th to 60th day of life; 12 h after the last exercise session animals were sacrificed and the cerebral cortex was dissected out. It is shown that homocysteine reduces glutamate uptake increases thiobarbituric acid-reactive substances and disrupts enzymatic antioxidant defenses in cerebral cortex. Physical activity reversed the homocysteine effects on glutamate uptake and on antioxidant enzymes activities; although the increase in thiobarbituric acid-reactive substances was only partially reversed by exercise. These findings allow us to suggest that physical exercise may have a protective role against homocysteine-induced oxidative imbalance and brain damage to the glutamatergic system.
Assuntos
Encefalopatias Metabólicas/terapia , Terapia por Exercício/métodos , Ácido Glutâmico/metabolismo , Hiper-Homocisteinemia/terapia , Estresse Oxidativo/fisiologia , Condicionamento Físico Animal/fisiologia , Animais , Animais Recém-Nascidos , Encefalopatias Metabólicas/fisiopatologia , Modelos Animais de Doenças , Hiper-Homocisteinemia/fisiopatologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
This study investigated whether physical exercise would reverse proline-induced performance deficits in water maze tasks, as well as its effects on brain-derived neurotrophic factor (BDNF) immunocontent and brain acetylcholinesterase (AChE) activity in Wistar rats. Proline administration followed partial time (6th-29th day of life) or full time (6th-60th day of life) protocols. Treadmill exercise was performed from 30th to 60th day of life, when behavioral testing was started. After that, animals were sacrificed for BDNF and AChE determination. Results show that proline impairs cognitive performance, decreases BDNF in cerebral cortex and hippocampus and increases AChE activity in hippocampus. All reported effects were prevented by exercise. These results suggest that cognitive, spatial learning/memory, deficits caused by hyperprolinemia may be associated, at least in part, to the decrease in BDNF levels and to the increase in AChE activity, as well as support the role of physical exercise as a potential neuroprotective strategy.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Transtornos Cognitivos/terapia , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Condicionamento Físico Animal , 1-Pirrolina-5-Carboxilato Desidrogenase/deficiência , Acetilcolinesterase/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/psicologia , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Masculino , Prolina Oxidase/deficiência , Ratos , Ratos WistarRESUMO
Considering that Na(+),K(+)-ATPase is an embedded-membrane enzyme and that experimental chronic hyperprolinemia decreases the activity of this enzyme in brain synaptic plasma membranes, the present study investigated the effect of chronic proline administration on thiobarbituric acid-reactive substances, as well as the influence of antioxidant vitamins E plus C on the effects mediated by proline on Na(+),K(+)-ATPase activity in cerebral cortex of rats. The expression of Na(+),K(+)-ATPase catalytic subunits was also evaluated. Results showed that proline increased thiobarbituric acid-reactive substances, suggesting an increase of lipid peroxidation. Furthermore, concomitant administration of vitamins E plus C significantly prevented the increase of lipid peroxidation, as well as the inhibition of Na(+),K(+)-ATPase activity caused by proline. We did not observe any change in levels of Na(+),K(+)-ATPase mRNA transcripts after chronic exposure to proline and vitamins E plus C. These findings provide insights into the mechanisms through which proline exerts its effects on brain function and suggest that treatment with antioxidants may be beneficial to treat neurological dysfunctions present in hyperprolinemic patients.
Assuntos
Antioxidantes , Ácido Ascórbico , Córtex Cerebral/enzimologia , Peroxidação de Lipídeos/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , Vitamina E , 1-Pirrolina-5-Carboxilato Desidrogenase/deficiência , Erros Inatos do Metabolismo dos Aminoácidos/induzido quimicamente , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Análise de Variância , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Ácido Ascórbico/metabolismo , Ácido Ascórbico/farmacologia , Córtex Cerebral/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , Expressão Gênica/efeitos dos fármacos , Humanos , Estresse Oxidativo/efeitos dos fármacos , Prolina/administração & dosagem , Prolina/efeitos adversos , Prolina Oxidase/deficiência , Prolina Oxidase/metabolismo , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Membranas Sinápticas/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Vitamina E/metabolismo , Vitamina E/farmacologiaRESUMO
Perinatal hypoxia-ischemia (HI) gives rise to inadequate substrate supply to the brain tissue, resulting in damage to neural cells. Previous studies at different time points of development, and with different animal species, suggest that the HI insult causes oxidative damage and changes Na+, K+-ATPase activity, which is known to be very susceptible to free radical-related lipid peroxidation. The aim of the present study was to establish the onset of the oxidative damage response in neonatal Wistar rats subjected to brain HI, evaluating parameters of oxidative stress, namely nitric oxide production, lipoperoxidation by thiobarbituric acid reactive substances (TBA-RS) production and malondialdehyde (MDA) levels, reactive species production by DCFH oxidation, antioxidant enzymatic activities of catalase, glutathione peroxidase, superoxide dismutase as well as Na+, K+-ATPase activity in hippocampus and cerebral cortex. Rat pups were subjected to right common carotid ligation followed by exposure to a hypoxic atmosphere (8% oxygen and 92% nitrogen) for 90 min. Animals were sacrificed by decapitation 0, 1 and 2 h after HI and both hippocampus and cerebral cortex from the right hemisphere (ipsilateral to the carotid occlusion) were dissected out for further experimentation. Results show an early decrease of Na+, K+-ATPase activity (at 0 and 1 h), as well as a late increase in MDA levels (2 h) and superoxide dismutase activity (1 and 2 h after HI) in the hippocampus. There was a late increase in both MDA levels and DCFH oxidation (1 and 2 h) and an increase in superoxide dismutase activity (2 h after HI) in cortex; however Na+, K+-ATPase activity remained unchanged. We suggest that neonatal HI induces oxidative damage to both hippocampus and cortex, in addition to a decrease in Na+, K+-ATPase activity in hippocampus early after the insult. These events might contribute to the later morphological damage in the brain and indicate that it would be essential to pursue neuroprotective strategies, aimed to counteract oxidative stress, as early as possible after the HI insult.