RESUMO
This study investigated the effects of subchronic administration of lead (Pb) acetate on thiobarbituric acid reactive substances (TBARS), total sulfhydryl content, protein carbonyl content, antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSHPx]), acetylcholinesterase (AChE), and Na+K+ATPase in the cerebral structures of rats. Male Wistar rats aged 60 days were treated with saline (control group) or Pb (treatment group), at various doses, by gavage, once a day for 35 days. The animals were sacrificed twelve hours after the last administration, and the cerebellum, hippocampus and cerebral cortex were removed. The results showed that Pb did not alter the evaluated oxidative stress parameters. Furthermore, Pb (64 and/or 128 mg/kg) altered SOD in the cerebellum, cerebral cortex and hippocampus. Pb (128 mg/kg) altered CAT in the cerebellum and cerebral cortex and GSHPx in the cerebral cortex. Also, Pb (64 mg/kg and 128 mg/kg) altered GSHPx in the cerebellum. Moreover, Pb (128 mg/kg) increased AChE in the hippocampus and decreased Na+K+ATPase in the cerebellum and hippocampus. In conclusion, subchronic exposure to Pb (occupational and environmental intoxication) altered antioxidant enzymes, AChE, and Na+K+ATPase, contributing to cerebral dysfunction.
Assuntos
Acetilcolinesterase , Antioxidantes , Ratos , Masculino , Animais , Antioxidantes/metabolismo , Acetilcolinesterase/metabolismo , Ratos Wistar , Carbonilação Proteica , Chumbo/toxicidade , Chumbo/metabolismo , Estresse Oxidativo , Catalase/metabolismo , Córtex Cerebral/metabolismo , Superóxido Dismutase/metabolismo , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/farmacologia , Encéfalo/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/farmacologiaRESUMO
Mild hyperhomocysteinemia is a risk factor for psychiatric and neurodegenerative diseases, whose mechanisms between them are not well-known. In the present study, we evaluated the emotional behavior and neurochemical pathways (ATPases, glutamate homeostasis, and cell viability) in amygdala and prefrontal cortex rats subjected to mild hyperhomocysteinemia (in vivo studies). The ex vivo effect of homocysteine on ATPases and redox status, as well as on NMDAR antagonism by MK-801 in same structures slices were also performed. Wistar male rats received a subcutaneous injection of 0.03 µmol Homocysteine/g of body weight or saline, twice a day from 30 to 60th-67th days of life. Hyperhomocysteinemia increased anxiety-like behavior and tended to alter locomotion/exploration of rats, whereas sucrose preference and forced swimming tests were not altered. Glutamate uptake was not changed, but the activities of glutamine synthetase and ATPases were increased. Cell viability was not altered. Ex vivo studies (slices) showed that homocysteine altered ATPases and redox status and that MK801, an NMDAR antagonist, protected amygdala (partially) and prefrontal cortex (totally) effects. Taken together, data showed that mild hyperhomocysteinemia impairs the emotional behavior, which may be associated with changes in ATPase and glutamate homeostasis, including glutamine synthetase and NMDAR overstimulation that could lead to excitotoxicity. These findings may be associated with the homocysteine risk factor on psychiatric disorders development and neurodegeneration.
Assuntos
Hiper-Homocisteinemia , Animais , Ansiedade , Encéfalo/metabolismo , Maleato de Dizocilpina/farmacologia , Glutamato-Amônia Ligase/metabolismo , Ácido Glutâmico/metabolismo , Homocisteína , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/metabolismo , Masculino , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/metabolismo , Roedores/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Sacarose/metabolismoRESUMO
Sepsis is a severe disease characterized by an uncontrolled systemic inflammation and consequent organ dysfunction generated in response to an infection. Extracellular ATP acting through the P2X7 receptor induces the maturation and release of pro-inflammatory cytokines (i.e., IL-1ß) and the production of reactive nitrogen and oxygen species that lead to oxidative tissue damage. Here, we investigated the role of the P2X7 receptor in inflammation, oxidative stress, and liver injury in sepsis. Sepsis was induced by cecal ligation and puncture (CLP) in wild-type (WT) and P2X7 knockout (P2X7-/-) mice. The oxidative stress in the liver of septic mice was assessed by 2',7'-dichlorofluorescein oxidation reaction (DCF), thiobarbituric acid-reactive substances (TBARS), and nitrite levels dosage. The status of the endogenous defense system was evaluated through catalase (CAT) and superoxide dismutase (SOD) activities. The inflammation was assessed histologically and by determining the expression of inflammatory cytokines and chemokines by RT-qPCR. We observed an increase in the reactive species and lipid peroxidation in the liver of septic WT mice, but not in the liver from P2X7-/- animals. We found an imbalance SOD/CAT ratio, also only WT septic animals. The number of inflammatory cells and the gene expression of IL-1 ß, IL-6, TNF-α, IL-10, CXCL1, and CXCL2 were higher in the liver of WT septic mice in comparison to P2X7-/- septic animals. In summary, our results suggest that the P2X7 receptor might be a therapeutic target to limit oxidative stress damage and liver injury during sepsis.
Assuntos
Hepatopatias/metabolismo , Estresse Oxidativo/fisiologia , Receptores Purinérgicos P2X7/metabolismo , Sepse/metabolismo , Sepse/patologia , Animais , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Kynurenic acid (KYNA) and quinolinic acid (QUIN) are metabolites formed in the degradation of tryptophan (Trp). QUIN is a selective NMDA receptor antagonist and may exert neurotoxic effects, whereas KYNA is an agonist of glutamatergic and cholinergic receptors and presents antioxidant properties. KYNA/QUIN ratio is decreased in several central nervous system disorders, but the mechanisms involved are not well elucidated. In the present study, we try to determine the neuroprotective capacity of KYNA on the QUIN effects in redox homeostasis changes (H2DCF oxidation, superoxide dismutase/catalase (SOD/CAT) ratio, glutathione peroxidase (GPx) activity, sulfhydryl content, and nitrite levels), as well as on inflammatory parameters (levels of TNF-α, IL-1ß, and IL-6). KYNA and QUIN effects on the activities of Na+,K+-ATPase and acetylcholinesterase (AChE) were also evaluated. Thirty-day-old male Wistar rats underwent stereotactic surgery and received intrastriatal injections as follows: group 1-control (PBS-injected), group 2-KYNA (100 µM), group 3-QUIN (150 nM), and group 4-KYNA + QUIN (KYNA-injected followed QUIN-injected). Results demonstrated that the KYNA administration was able to prevent the increase in reactive oxygen species, SOD/CAT ratio, and pro-inflammatory cytokines (IL-1ß and IL-6) and the decrease in GPx activity, sulfhydryl content, and nitrite levels caused by QUIN. KYNA was also able to partially prevent the decrease in Na+,K+-ATPase activity and the increase in AChE activity caused by QUIN. This study may help in the elucidation of neuroprotective effects of KYNA against oxidative and inflammatory insults caused by QUIN in the striatum of young male Wistar rats.
Assuntos
Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Encefalite/metabolismo , Homeostase/efeitos dos fármacos , Ácido Cinurênico/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Oxirredução/efeitos dos fármacos , Ácido Quinolínico/administração & dosagem , Animais , Antioxidantes/administração & dosagem , Encefalite/induzido quimicamente , Mediadores da Inflamação/metabolismo , Masculino , Ratos Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inibidoresRESUMO
The aim of this study was to investigate the effect of the chronic administration of methionine (Met) and/or its metabolite, methionine sulfoxide (MetO), on the behavior and neurochemical parameters of young rats. Rats were treated with saline (control), Met (0.2-0.4 g/kg), MetO (0.05-0.1 g/kg), and/or a combination of Met + MetO, subcutaneously twice a day from postnatal day 6 (P6) to P28. The results showed that Met, MetO, and Met + MetO impaired short-term and spatial memories (P < 0.05), reduced rearing and grooming (P < 0.05), but did not alter locomotor activity (P > 0.05). Acetylcholinesterase activity was increased in the cerebral cortex, hippocampus, and striatum following Met and/or MetO (P < 0.05) treatment, while Na+, K+-ATPase activity was reduced in the hippocampus (P < 0.05). There was an increase in the level of thiobarbituric acid reactive substances (TBARS) in the cerebral cortex in Met-, MetO-, and Met + MetO-treated rats (P < 0.05). Met and/or MetO treatment reduced superoxide dismutase, catalase, and glutathione peroxidase activity, total thiol content, and nitrite levels, and increased reactive oxygen species and TBARS levels in the hippocampus and striatum (P < 0.05). Hippocampal brain-derived neurotrophic factor was reduced by MetO and Met + MetO compared with the control group. The number of NeuN-positive cells was decreased in the CA3 in Met + MetO group and in the dentate gyrus in the Met, MetO, and Met + MetO groups compared to control group (P < 0.05). Taken together, these findings further increase our understanding of changes in the brain in hypermethioninemia by elucidating behavioral alterations, biological mechanisms, and the vulnerability of brain function to high concentrations of Met and MetO.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/complicações , Glicina N-Metiltransferase/deficiência , Hipocampo/patologia , Transtornos da Memória/etiologia , Transtornos da Memória/patologia , Metionina/análogos & derivados , Espécies Reativas de Oxigênio/metabolismo , Acetilcolinesterase/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/induzido quimicamente , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Animais , Catalase/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Feminino , Glutationa Peroxidase/deficiência , Glicina N-Metiltransferase/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Transtornos da Memória/metabolismo , Memória de Curto Prazo/efeitos dos fármacos , Metionina/metabolismo , Metionina/toxicidade , Ratos , Ratos Wistar , Memória Espacial/efeitos dos fármacos , Superóxido Dismutase/deficiência , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Astrocytes are dynamic glial cells that maintain brain homeostasis, particularly metabolic functions, inflammatory response, and antioxidant defense. Since menopause may be associated with brain dysfunction, in the present study, we evaluated anti- and proinflammatory cytokine release in cortical and hippocampal astrocyte cultures obtained from adult female Wistar rats subjected to ovariectomy, a known experimental model of menopause. We also tested some parameters of metabolic functionality (Na+, K+-ATPase activity) and cellular redox status, such as antioxidant enzyme defenses (superoxide dismutase and catalase) and the intracellular production of reactive oxygen species in this experimental model. Female adult Wistar rats (180 days-age) were assigned to one of the following groups: sham (submitted to surgery without removal of the ovaries) and ovariectomy (submitted to surgery to removal of the ovaries). Thirty days after ovariectomy or sham surgery, we prepared astrocyte cultures from control and ovariectomy surgery animals. Ovariectomized rats presented an increase in pro-inflammatory cytokines (tumor necrosis factor α, interleukins 1ß, 6, and 18) and a decrease in interleukin 10 release, an anti-inflammatory cytokine, in cortical and hippocampal astrocytes, when compared to those obtained from sham group (control). In addition, Na+,K+-ATPase activity decreased in hippocampal astrocytes, but not in cortical astrocyte cultures. In contrast, antioxidant enzymes did not alter in cortical astrocyte cultures, but increased in hippocampal astrocytes. In summary, our findings suggest that ovariectomy is able to induce an inflammatory response in vivo, which could be detected in in vitro astrocytes after approximately 4 weeks.
Assuntos
Astrócitos/metabolismo , Mediadores da Inflamação/metabolismo , Ovariectomia/efeitos adversos , Estresse Oxidativo/fisiologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Astrócitos/patologia , Células Cultivadas , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Feminino , Hipocampo/metabolismo , Hipocampo/patologia , Ovariectomia/tendências , Oxirredução , Ratos , Ratos WistarRESUMO
Homocysteine (HCY) has been linked to oxidative stress and varied metabolic changes that are dependent on its concentration and affected tissues. In the present study we evaluate parameters of energy metabolism [succinate dehydrogenase (SDH), complex II and IV (cytochrome c oxidase), and ATP levels] and oxidative stress [DCFH oxidation, nitrite levels, antioxidant enzymes and lipid, protein and DNA damages, as well as nuclear factor erythroid 2-related (Nrf2) protein abundance] in amygdala and prefrontal cortex of HCY-treated rats. Wistar male rats were treated with a subcutaneous injection of HCY (0.03 µmol/g of body weight) from the 30th to 60th post-natal day, twice a day, to induce mild hyperhomocysteinemia (HHCY). The rats were euthanatized without anesthesia at 12 h after the last injection, and amygdala and prefrontal cortex were dissected for biochemical analyses. In the amygdala, mild HHCY increased activities of SDH and complex II and decreased complex IV and ATP level, as well as increased antioxidant enzymes activities (glutathione peroxidase and superoxide dismutase), nitrite levels, DNA damage, and Nrf 2 protein abundance. In the prefrontal cortex, mild HHCY did not alter energy metabolism, but increased glutathione peroxidase, catalase and DNA damage. Other analyzed parameters were not altered by HCY-treatment. Our findings suggested that chronic mild HHCY changes each brain structure, particularly and specifically. These changes may be associated with the mechanisms by which chronic mild HHCY has been linked to the risk factor of fear, mood disorders and depression, as well as in neurodegenerative diseases.
Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Dano ao DNA , Hiper-Homocisteinemia/metabolismo , Hiper-Homocisteinemia/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Tonsila do Cerebelo/enzimologia , Tonsila do Cerebelo/patologia , Animais , Antioxidantes/metabolismo , Núcleo Celular/metabolismo , Doença Crônica , Metabolismo Energético , Masculino , Modelos Biológicos , Córtex Pré-Frontal/enzimologia , Córtex Pré-Frontal/patologia , Ratos WistarRESUMO
The aim of this study was to verify the effects of ovariectomy (OVX) and/or vitamin D supplementation (VIT D) on inflammatory and cholinergic parameters in hippocampus, as well as on serum estradiol and VIT D levels of rats. Ninety-day-old female Wistar rats were randomly divided into four groups: SHAM, OVX, VIT D or OVX + VIT D. Thirty days after OVX, VIT D (500 IU/kg/day) was supplemented by gavage, for 30 days. Approximately 12 h after the last VIT D administration, rats were euthanized and hippocampus and serum were obtained for further analyses. Results showed that OVX rats presented a decrease in estradiol levels when compared to control (SHAM). There was an increase in VIT D levels in the groups submitted to VIT D supplementation. OVX increased the immunocontent of nuclear p-NF-κB/p65, TNF-α and IL-6 levels. VIT D partially reversed the increase in p-NF-κB/p65 immunocontent and IL-6 levels. Regarding cholinergic system, OVX caused an increase in acetylcholinesterase activity without changing acetylcholinesterase and choline acetyltransferase immunocontents. VIT D did not reverse the increase in acetylcholinesterase activity caused by OVX. These results demonstrate that OVX alters inflammatory and cholinergic parameters and that VIT D supplementation, at the dose used, partially reversed the increase in immunocontent of p-NF-Kb/p65 and IL-6 levels, but it was not able to reverse other parameters studied. Our findings may help in the understanding of the brain changes that occurs in post menopause period and open perspectives for futures research involving VIT D therapies.
Assuntos
Acetilcolinesterase/metabolismo , Hipocampo/efeitos dos fármacos , Interleucina-6/metabolismo , Fator de Transcrição RelA/metabolismo , Vitamina D/farmacologia , Análise de Variância , Animais , Peso Corporal/efeitos dos fármacos , Calcifediol/sangue , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citocinas/metabolismo , Citosol/efeitos dos fármacos , Citosol/metabolismo , Suplementos Nutricionais , Ingestão de Alimentos/efeitos dos fármacos , Estradiol/sangue , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Ovariectomia , Ratos , Ratos WistarRESUMO
The aim of this study was to investigate the effect of ovariectomy (OVX), a surgical model of menopause, and/or vitamin D (VIT D) supplementation on oxidative status, DNA damage, and telomere length in hippocampus of rats at two ages. Ninety-day-old (adult) or 180-day-old (older) female Wistar rats were divided into four groups: SHAM, OVX, VIT D, and OVX + VIT D. Thirty days after OVX, rats were supplemented with VIT D (500 IU/kg) by gavage, for a period of 30 days. Results showed that OVX altered antioxidant enzymes, increasing the activities of catalase in adult rats and superoxide dismutase in older rats. VIT D per se increased the activities of catalase and superoxide dismutase in older rats, but not in adult rats. VIT D supplementation to OVX (OVX + VIT D) rats did not reverse the effect of OVX on catalase in adult rats, but it partially reversed the increase in superoxide dismutase activity in older rats. OVX increased DNA damage in hippocampus of adult and older rats. VIT D per se reduced DNA damage, and when associated to OVX, it partially reversed this alteration. Additionally, OVX caused a telomere shortening in older rats, and VIT D was able to reverse such effect. Taken together, these results demonstrate that surgical menopause in rats causes hippocampal biochemical changes and VIT D appears, at least in part, to act in a beneficial way.
Assuntos
Dano ao DNA/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Ovariectomia/efeitos adversos , Encurtamento do Telômero/fisiologia , Vitamina D/farmacologia , Fatores Etários , Animais , Catalase/metabolismo , Ensaio Cometa , Feminino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Estatísticas não Paramétricas , Superóxido Dismutase/metabolismo , Encurtamento do Telômero/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fatores de TempoRESUMO
Homocysteine is a sulfur-containing amino acid derived from methionine metabolism. When plasma homocysteine levels exceed 10-15 µM, there is a condition known as hyperhomocysteinemia, which occur as a result of an inborn error of methionine metabolism or by non-genetic causes. Mild hyperhomocysteinemia is considered a risk factor for development of neurodegenerative diseases. The objective of the present study was to evaluate whether acetylsalicylic acid has neuroprotective role on the effect of homocysteine on inflammatory, oxidative/nitrative stress, and morphological parameters in cerebral cortex of rats subjected to chronic mild hyperhomocysteinemia. Wistar male rats received homocysteine (0.03 µmol/g of body weight) by subcutaneous injections twice a day and acetylsalicylic acid (25 mg/Kg of body weight) by intraperitoneal injections once a day from the 30th to the 60th postpartum day. Control rats received vehicle solution in the same volume. Results showed that rats subjected to chronic mild hyperhomocysteinemia significantly increased IL-1ß, IL-6, and acetylcholinesterase activity and reduced nitrite levels. Homocysteine decreased catalase activity and immunocontent and superoxide dismutase activity, caused protein and DNA damage, and altered neurons ultrastructure. Acetylsalicylic acid totally prevented the effect of homocysteine on acetylcholinesterase activity and catalase activity and immunocontent, as well as the ultrastructural changes, and partially prevented alterations on IL-1ß levels, superoxide dismutase activity, sulfhydryl content, and comet assay. Acetylsalicylic acid per se increased DNA damage index. In summary, our findings showed that chronic chemically induced model of mild hyperhomocysteinemia altered some parameters and acetylsalicylic acid administration seemed to be neuroprotective, at least in part, on neurotoxicity of homocysteine.