RESUMO
The effect of combined-factors (hypoxia+copper) on the biochemical parameters and antioxidant defenses were studied in the neotropical fish Piaractus mesopotamicus. Fish were exposed for 48 h to 0.4 mg Cu(2+) L(-1) (0.4Cu), hypoxia=50 mm Hg (Hpx), and 0.4 mg Cu(2) L(-1)+hypoxia=50 mm Hg (0.4CuHpx). The exposure to 0.4Cu increased the reactive oxygen species (ROS) in the liver, accompanied by increases in superoxide dismutase (SOD) and decreases in catalase (CAT) activity, showing the influence of copper in this protection. The exposure to Hpx decreased the activity of glutathione peroxidase (GSH-Px) and CAT. Exposure to a combined-factor caused an increase in the ROS production followed by an increase in SOD and a decrease in GSH-Px and CAT. At 0.4Cu, fish presented a reduction in CAT, while in Hpx decreases in SOD, CAT and GSH-Px were observed in red muscles. Single-factors were insufficient to cause ROS production. In combined-factors, increased ROS formation and decreased SOD, CAT and GSH-Px were observed. RBC increased in all groups, but only under combined-factors was there an increase in hemoglobin. Copper plasma concentration increased in groups exposed to copper. Na(+)/K(+)-ATPase activity in gills decreased in 0.4Cu and 0.4CuHpx, and increased in Hpx. Metallothionein concentration in gills increased under combined-factors. Combined-factors caused significant disturbances in the antioxidant defenses and biochemical parameters than single-factors.
Assuntos
Antioxidantes/metabolismo , Sulfato de Cobre/toxicidade , Peixes/metabolismo , Brânquias/efeitos dos fármacos , Hipóxia/metabolismo , Fígado/efeitos dos fármacos , Fibras Musculares de Contração Rápida/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Catalase/metabolismo , Sulfato de Cobre/sangue , Contagem de Eritrócitos , Proteínas de Peixes/metabolismo , Brânquias/enzimologia , Brânquias/metabolismo , Glutationa Peroxidase/metabolismo , Hipóxia/sangue , Hipóxia/enzimologia , Fígado/enzimologia , Fígado/metabolismo , Metalotioneína/metabolismo , Fibras Musculares de Contração Rápida/enzimologia , Fibras Musculares de Contração Rápida/metabolismo , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/sangueRESUMO
BACKGROUND: Copper (Cu) is an essential trace element for many biological processes including maintenance of both innate and acquired branches of immunity. OBJECTIVE: To measure the effect of copper supplementation on IL-2 and TNF-alpha production in subjects with lower and higher ceuloplasmin (Cp) values within normal range. DESIGN: Healthy adults (17 men and 16 women) with normal-low (low Cp) and normal-high Cp (high Cp) values were supplemented with 10 mg Cu/day (as CuSO(4)) during 2 months. METHOD: Before and after supplementation blood mononuclear cells were incubated in the absence or presence of phytohaemagglutinin or lipopolysaccharide for induction of IL-2 and TNF-alpha, respectively. The secretion of cytokines was measured by ELISA. Cu supplementation did not modify classical biochemical markers of Cu status. RESULTS: After supplementation, a significant increase in IL-2 production was found only in subjects with normal-low plasma Cp. Before and after Cu supplementation geometric mean and range +/- 1 SEM values were 1,566 (1,287-1,905) and 2,514 (2,159-2,927) pg/mL, respectively (two-way ANOVA for repeated measures: Cp level p < 0.001; time = NS; interaction Cp level and time p < 0.05). We did not observe changes in TNF-alpha production after Cu supplementation. CONCLUSIONS: Cu supplementation increased secretion of IL-2 and not TNF-alpha, which suggests an activation of proliferative but not inflammatory cytokines. These results support hypothesis that IL-2 may be a good indicator to identify a subgroup of individuals (polymorphism) who differs in Cu metabolism.