Assuntos
Crassostrea/microbiologia , Crassostrea/virologia , Herpesviridae/isolamento & purificação , Vibrio/isolamento & purificação , Animais , Brasil/epidemiologia , DNA Bacteriano , DNA Viral , Infecções por Herpesviridae/veterinária , Reação em Cadeia da Polimerase/veterinária , Vibrioses/veterináriaRESUMO
In this study we hypothesized that swimming during sensitization phase could result in a preventive effect in mice with allergic asthma. Swiss mice were divided into 4 groups: Control and Swimming (non-sensitized), OVA and OVA+Swimming (sensitized). The allergic inflammation was induced by 2 intraperitoneal injections and 4 aerosol challenges using ovalbumin. Swimming sessions were performed at high intensity over 3 weeks. 48 h after the last challenge mice were euthanized. Swimming decreased OVA-increased total IgE, IL-1, IL-4, IL-5 and IL-6 levels, as well as the number of total cells, lymphocytes and eosinophils in bronchoalveolar lavage fluid, (p<0.05). Simultaneously, swimming also increased IL-10 and glutathione levels in the Swimming and OVA+Swimming groups (p<0.05). The levels of glutathione peroxidase and catalase were increased only in the Swimming group when compared to all groups (p<0.05). 21 days of swimming resulted in an attenuation of pulmonary allergic inflammation followed by an increase of glutathione levels in the OVA group. Swimming only increased the levels of glutathione peroxidase and catalase in non-sensitized mice (p<0.05). These data suggest that the pulmonary anti-inflammatory effects produced by 3 weeks of high-intensity swimming in this model of OVA-induced asthma may be, at least partly, modulated by reduced oxidative stress and increased IL-10 production.
Assuntos
Asma/prevenção & controle , Inflamação/prevenção & controle , Estresse Oxidativo/fisiologia , Natação/fisiologia , Animais , Asma/imunologia , Líquido da Lavagem Broncoalveolar/imunologia , Modelos Animais de Doenças , Glutationa/metabolismo , Inflamação/imunologia , Interleucina-10/imunologia , Masculino , Camundongos , Ovalbumina/imunologia , OxirreduçãoRESUMO
We evaluated the potential neuroprotective effect of 1-100 µM of four organoselenium compounds: diphenyl diselenide, 3’3-ditri-fluoromethyldiphenyl diselenide, p-methoxy-diphenyl diselenide, and p-chloro-diphenyl diselenide, against methylmercury-induced mitochondrial dysfunction and oxidative stress in mitochondrial-enriched fractions from adult Swiss mouse brain. Methylmercury (10-100 µM) significantly decreased mitochondrial activity, assessed by MTT reduction assay, in a dose-dependent manner, which occurred in parallel with increased glutathione oxidation, hydroperoxide formation (xylenol orange assay) and lipid peroxidation end-products (thiobarbituric acid reactive substances, TBARS). The co-incubation with diphenyl diselenide (100 µM) completely prevented the disruption of mitochondrial activity as well as the increase in TBARS levels caused by methylmercury. The compound 3’3-ditrifluoromethyldiphenyl diselenide provided a partial but significant protection against methylmercury-induced mitochondrial dysfunction (45.4 ± 5.8 percent inhibition of the methylmercury effect). Diphenyl diselenide showed a higher thiol peroxidase activity compared to the other three compounds. Catalase blocked methylmercury-induced TBARS, pointing to hydrogen peroxide as a vector during methylmercury toxicity in this model. This result also suggests that thiol peroxidase activity of organoselenium compounds accounts for their protective actions against methylmercury-induced oxidative stress. Our results show that diphenyl diselenide and potentially other organoselenium compounds may represent important molecules in the search for an improved therapy against the deleterious effects of methylmercury as well as other mercury compounds.
Assuntos
Animais , Masculino , Camundongos , Encéfalo/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Intoxicação do Sistema Nervoso por Mercúrio/prevenção & controle , Compostos de Metilmercúrio/toxicidade , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Compostos Organosselênicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Análise de Variância , Derivados de Benzeno/farmacologia , Fracionamento Celular , Modelos Animais , Fármacos Neuroprotetores/classificação , Compostos Organosselênicos/químicaRESUMO
We evaluated the potential neuroprotective effect of 1-100 µM of four organoselenium compounds: diphenyl diselenide, 3'3-ditri-fluoromethyldiphenyl diselenide, p-methoxy-diphenyl diselenide, and p-chloro-diphenyl diselenide, against methylmercury-induced mitochondrial dysfunction and oxidative stress in mitochondrial-enriched fractions from adult Swiss mouse brain. Methylmercury (10-100 µM) significantly decreased mitochondrial activity, assessed by MTT reduction assay, in a dose-dependent manner, which occurred in parallel with increased glutathione oxidation, hydroperoxide formation (xylenol orange assay) and lipid peroxidation end-products (thiobarbituric acid reactive substances, TBARS). The co-incubation with diphenyl diselenide (100 µM) completely prevented the disruption of mitochondrial activity as well as the increase in TBARS levels caused by methylmercury. The compound 3'3-ditrifluoromethyldiphenyl diselenide provided a partial but significant protection against methylmercury-induced mitochondrial dysfunction (45.4 ± 5.8% inhibition of the methylmercury effect). Diphenyl diselenide showed a higher thiol peroxidase activity compared to the other three compounds. Catalase blocked methylmercury-induced TBARS, pointing to hydrogen peroxide as a vector during methylmercury toxicity in this model. This result also suggests that thiol peroxidase activity of organoselenium compounds accounts for their protective actions against methylmercury-induced oxidative stress. Our results show that diphenyl diselenide and potentially other organoselenium compounds may represent important molecules in the search for an improved therapy against the deleterious effects of methylmercury as well as other mercury compounds.
Assuntos
Encéfalo/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Intoxicação do Sistema Nervoso por Mercúrio/prevenção & controle , Compostos de Metilmercúrio/toxicidade , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Compostos Organosselênicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Análise de Variância , Animais , Derivados de Benzeno/farmacologia , Fracionamento Celular , Masculino , Camundongos , Modelos Animais , Fármacos Neuroprotetores/classificação , Compostos Organosselênicos/químicaRESUMO
The cellular prion protein (PrP(C)) is a neuronal-anchored glycoprotein that has been associated with various functions in the CNS such as synaptic plasticity, cognitive processes and neuroprotection. Here we investigated age-related behavioral and neurochemical alterations in wild-type (Prnp(+/+)), PrP(C) knockout (Prnp(0/0)) and the PrP(C) overexpressing Tg-20 mice. Three- or 11 month-old animals were submitted to a battery of behavioral tasks including open field, activity cages, elevated plus-maze, social recognition and inhibitory avoidance tasks. The 11 month-old Prnp(+/+) and Prnp(0/0) mice exhibited significant impairments in their locomotor activity and social recognition memory and increased anxiety-related responses. Remarkably, Tg-20 mice did not present these age-related impairments. The i.c.v. infusion of STI1 peptide 230-245, which includes the PrP(C) binding site, improved the age-related social recognition deficits in Prnp(+/+). In comparison with the two other age-matched genotypes, the 11 month-old Tg-20 mice also exhibited reduced activity of seric acetylcholinesterase, increased expression of the protein synaptophysin and decreased caspase-3 positive-cells in the hippocampus. The present findings obtained with genetic and pharmacological approaches provide convincing evidence that PrP(C) exerts a critical role in the age-related behavioral deficits in mice probably through adaptive mechanisms including apoptotic pathways and synaptic plasticity.
Assuntos
Envelhecimento/metabolismo , Encéfalo/metabolismo , Demência/metabolismo , Proteínas PrPC/metabolismo , Acetilcolinesterase/metabolismo , Envelhecimento/genética , Animais , Transtornos de Ansiedade/genética , Transtornos de Ansiedade/metabolismo , Transtornos de Ansiedade/fisiopatologia , Apoptose/genética , Comportamento Animal/fisiologia , Encéfalo/fisiopatologia , Caspase 3/metabolismo , Demência/genética , Demência/fisiopatologia , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/genética , Transtornos da Memória/metabolismo , Transtornos da Memória/fisiopatologia , Camundongos , Camundongos Knockout , Plasticidade Neuronal/genética , Testes Neuropsicológicos , Fragmentos de Peptídeos/farmacologia , Proteínas PrPC/genética , Estrutura Terciária de Proteína/genética , Sinaptofisina/metabolismoRESUMO
Time courses of total (GSH-t), disulfide (GSSG), and mixed disulfide (PSSG) forms of glutathione were studied in chicken blood submitted to oxidative stress induced by diamide or by the reactive oxygen species (ROS)-producing system xanthine/xanthine oxidase (X/XO). Diamide-treated blood induced an immediate increase in GSSG and PSSG, while X/XO produced a slow and sustained stress with increased values of GSSG and PSSG only after 30 and/or 60 min of incubation. Both total protein S-thiolation (mixed disulfide with glutathione) and dethiolation and hemoglobin A S-thiolation and dethiolation were clearly observed. Hemoglobin A (Hb A) was the major S-thiolated protein. We further characterized chicken Hb S-thiolation through the reaction of Hb with GSSG or the GSH/GSSG redox couple. Methemoglobin levels did not change with diamide or with X/XO treatment. Present results suggest that the most reactive cysteine pair of Hb A, the major chicken Hb, might function as an antioxidant under in vivo oxidative stress conditions.
Assuntos
Diamida/farmacologia , Hemoglobina A/metabolismo , Líquido Intracelular/metabolismo , Estresse Oxidativo , Compostos de Sulfidrila/sangue , Xantina Oxidase/farmacologia , Animais , Galinhas , Eritrócitos/metabolismo , Glutationa/sangue , Dissulfeto de Glutationa/sangue , Hemoglobina A/química , Oxirredução/efeitos dos fármacosRESUMO
Starch gel electrophoresis pH 8.6, or PAGE pH 8.9, of the scalloped hammerhead shark hemolysates showed three hemoglobins (Hb). An additional Hb between the two most mobile electrophoretic components was seen in starch gel electrophoresis, pH 8.1, and also in highly loaded PAGE gels. The relative concentration of these Hbs was variable among individuals, when accessed at pH 8.1. Dilution of hemolysates led to a redistribution of the Hb tetramer subunits. Under denaturing conditions, the unfractionated hemolysate was resolved in 3 Hb subunits. Isolated Hbs, named SL I-SL IV, showed unusual subunit compositions: SL I, the least mobile, is "b3c"; SL II is "a2bc"; SL III and SL IV are composed only by "a" subunits. Hemoglobins in the whole hemolysate have an average of two reactive cysteines per tetramer, which were not easily S-thiolated by glutathione, as is the case for related species. After hemoglobin denaturation, six additional -SH groups were titrated by Ellman's reagent. Methemoglobin content was low in the erythrocytes of nine examined specimens, 1.13 +/- 1.90%. High values for total erythrocyte glutathione (GSH) were found: 4.5 +/- 0.7 mM; n = 7. The ratio of 1.4 +/- 0.4 GSH/Hb is higher than usually reported for mammalians.
Assuntos
Glutationa/sangue , Hemoglobinas/química , Tubarões/sangue , Compostos de Sulfidrila/análise , Animais , Eletroforese/métodos , Eritrócitos/química , Glutationa/análogos & derivados , Glutationa/química , Dissulfeto de Glutationa , Hematócrito , Concentração de Íons de Hidrogênio , Metemoglobina/análise , Metemoglobina/química , Amido , Compostos de Sulfidrila/químicaRESUMO
1. Adult chicken hemoglobins Hb A and Hb D interact with glutathione disulfide, GSSG. The major hemoglobin, Hb A, forms at least two new components, termed GHb AI and GHb AII, and Hb D forms at least one, GHb DI. 2. At pH 8.0 and 5 degrees C, glutathione disulfide (GSSG) in a molar excess of 50 x took 6 days to complete the reaction, although at pH 8.6 and 41 degrees C only 1 hr was needed, where the hemoglobins Hb A and Hb D were converted to their most mobile forms GHb AII and GHb DI. 3. Slight molar excess (2.7 GSSG/Hb, pH 7.4, 41 degrees C), reacting for 1 hr, showed extensive formation of GHb AI and some GHb AII. 4. Electrophoretic patterns, from the reaction products of 54 GSSG/Hb excess at different times, showed a marked pH dependence. 5. Titration with pCMB (p-chloromercuribezoic acid) of DTE (dithioerythrytol)-reduced samples showed 8.0 +/- 0.4 (N = 5) -SH (sulfhydryl) per tetramer. In hemolysates not reacted with DTE, 6.0 +/- 0.4 (N = 3) -SH were detected. 6. DTE-reduced and GSSG-reacted hemoglobins showed 4.6 +/- 0.5 (N = 7) -SH and 1.5 +/- 0.4 (N = 6) -SH, respectively, as titrated by DTNB, pH 8.0. DTE-reduced hemoglobins showed four fast-reacting -SH groups, no longer present in GSSG-reacted hemoglobins. 7. Our data indicate that chicken GHb AI and GHb DI probably have two glutathionyl residues per tetramer whereas GHb AII has four.(ABSTRACT TRUNCATED AT 250 WORDS)