Behaviour of the oxidant scavenger metallothionein in hypoxia-induced neotropical fish

The pacu (Piaractus mesopotamicus) is a hypoxia-tolerant neotropical fish species. There is little or no information in this species regarding biochemical adaptations to waters with different oxygen concentrations, such as the production of reactive oxygen species and antioxidant scavengers, which might be of interest in the study of antioxidant defense mechanisms. Metallothioneins (MT) have been widely applied as biomarkers for metal exposure in fish liver, and, recently, in bile. These metalloproteins, however, have also been reported as free radical scavengers, although studies in this regard are scarce in fish. In this context, normoxic and hypoxic controlled experiments were conducted with pacu specimens and MT levels were quantified in both liver and bile. Reduced glutathione (GSH) indicative of oxidative stress, and thiobarbituric acid reactive substances (TBARS), indicative of lipid peroxidation, were also determined in liver. The results demonstrate that hypoxic fish present significantly lower metallothionein levels in liver and bile and lower reduced glutathione levels in liver, whereas lipid peroxidation was not significantly different between hypoxic and normoxic fish. The results of the present study seem to suggest that metallothioneins may actively participate in redox regulation in hypoxic fish in both bile and liver. MT levels in these organs may be temporarily suppressed, supporting the notion that down-regulation of oxidant scavengers during the oxidative burst is important in defense signaling in these adapted organisms. (C) 2014 Elsevier Inc. All rights reserved.The pacu (Piaractus mesopotamicus) is a hypoxia-tolerant neotropical fish species. There is little or no information in this species regarding biochemical adaptations to waters with different oxygen concentrations, such as the production of reactive oxyge1032428sem informaçãosem informaçã

The effect of thiamine deficiency on inflammation, oxidative stress and cellular migration in an experimental model of sepsis

Made available in DSpace on 2015-05-27T13:39:48Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) raphael_coelhoetal_IOC_2014.pdf: 857144 bytes, checksum: 7c889baaa931dc516ab12d72c17aa8ef (MD5) Previous issue date: 2014Universidade do Estado do Rio de Janeiro (UERJ). Hospital Universitário Pedro Ernesto. Unidade de Cuidados Intensivos. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ).Instituto de Biologia. Cenrto Biomédico. Departamento de Bioquímica. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ).Instituto de Biologia. Cenrto Biomédico. Departamento de Bioquímica. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ).Instituto de Biologia. Cenrto Biomédico. Departamento de Bioquímica. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ).Instituto de Biologia. Cenrto Biomédico. Departamento de Bioquímica. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ).Instituto de Biologia. Cenrto Biomédico. Departamento de Bioquímica. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ).Instituto de Biologia. Cenrto Biomédico. Laboratório de Morfometria, Metabolismo e Cardiovascular. Rio de Janeiro, RJ, Brasil.Background Sepsis is a prevalent condition in critically ill patients and may be associated with thiamine deficiency (TD). The aim of this study was to evaluate the effect of TD on inflammation, oxidative stress and cellular recruitment in a sepsis model. Methods The experimental sepsis model, cecal ligation and puncture (CLP), was utilized on mice in comparison with a sham procedure. The following four groups were compared against each other: SHAM with AIN93G complete chow, SHAM with thiamine deficient (TD) chow, CLP with AIN93G complete chow, and CLP with TD chow. Thiamine pyrophosphate (TPP) blood concentrations were determined, and blood and peritoneal fluid were evaluated for differences in TNF-alpha, IL-1, IL-6, KC and MCP-1/CCL2 levels. In addition, the levels of 4-HNE adducts in liver proteins were evaluated by Western Blot. Results The mean TPP blood concentration from the mice fed with the complete chow was 303.3 ± 42.6 nmol/L, and TD occurred within 10 days. TNF-α and MCP-1 concentrations in the peritoneal fluid were significantly greater in the CLP with TD chow group when compared with the other groups. The blood IL-1β level, however, was lower in the CLP with TD chow group. Liver 4-HNE levels were highest in the TD chow groups. Blood mononuclear cell numbers, as well as peritoneal total leukocyte, mononuclear cell and neutrophil numbers were greater in the CLP with TD chow group. Peritoneal bacterial colony forming units (CFU) were significantly lower in the CLP with TD chow group. Conclusion TD was associated with greater bacterial clearance, oxidative stress and inflammatory response changes

Cytochrome P450 detection in liver of the catfish Ancistrus multispinis (Osteichthyes, Loricariidae)

Sensitive biological responses to environmental contaminants are useful as early warning signals to predict the damages by long-term exposure. Protocols standardization to quantify biochemical parameters in different fish species is required to validate its use as biomarkers. Comparative studies from different fish species and its interpretation are a challenge for the validation of its use as general biomarkers, representative of environmental impact. In this study, the protocol for liver cytochrome P450 (CYP) analysis from the native Brazilian fish Ancistrus multispinis was established. The microsome contamination by hemoglobin during the analysis of CYP in liver was detected, leading to misinterpretation of the results. The spectrophotometric method for CYP analysis was adapted in order to diminish the hemoglobin interference. Additionally, the western blotting method for CYP1A analysis was tested with success for this fish species.<br>Respostas biológicas sensíveis aos contaminantes ambientais são úteis para prever efeitos prejudiciais devido a exposições crônicas. Padronização de protocolos para quantificar parâmetros bioquímicos em diferentes espécies de peixes é necessária para validar o uso como biomarcador. Estudos comparativos de diferentes espécies de peixe e sua interpretação são um avanço para a validação do uso de biomarcadores gerais, representativos do impacto ambiental. Neste estudo o protocolo para a análise do citocromo P450 (CYP) do peixe nativo brasileiro Ancistrus multispinis foi estabelecido. Cyp é um biomarcador de exposição principalmente de hidrocarbonetos policíclicos aromáticos (HAP), bifenilas policloradas (PCB) e dioxinas. A contaminação do microssomo pela hemoglobina durante as análises do CYP no fígado foi detectada, levando a uma interpretação errônea dos resultados. O método espectrofotométrico para análise do CYP foi adaptado para diminuir a interferência da hemoglobina. Além disso, o método de western blotting para análise de CYP1A foi testado com sucesso para essa espécie de peixe