RESUMO
BACKGROUND: Selenium (Se) has been recognized as an essential micronutrient for nearly all forms of life. In recent decades, broiler responses to dietary Se supplemental levels and sources have received considerable attention. On environmental grounds, organic trace mineral utilization in practical broiler feeds has been defended due to its higher bioavailability. In such feeds, trace minerals are provided simultaneously in the same supplement as inorganic salts or organic chelates, a fact commonly ignored in assays conducted to validate organic trace mineral sources. The current assay aimed to investigate growth and biochemical responses, as well as Se retention of growing chicks fed diets supplemented with organic and inorganic Se levels and where the trace minerals (zinc, copper, manganese, and iron) were provided as organic chelates or inorganic salts according to Se source assessed. In so doing, a 2 × 5 factorial arrangement was used to investigate the effects of sodium selenite (SS) and selenium-yeast (SY) supplemented in feeds to provide the levels of 0, 0.08, 0.16, 0.24, and 0.32 mg Se/kg. RESULTS: Chicks fed selenium-yeast diets had body weight (BW), and average daily gain (ADG) maximized at 0.133 and 0.130 mg Se/kg, respectively. Both Se sources linearly increased (P < 0.05) the glutathione peroxidase (GSH-Px) activity in chick blood but higher values were observed in sodium selenite fed chicks (P < 0.05). Both Se sources influenced thyroid hormone serum concentrations (P < 0.05). Chicks fed SY exhibited greater retention of Se in the feathers (P < 0.05). Relative bioavailability of selenium yeast compared with SS for the Se content in carcass, feathers, total and Se retention were, 126, 116, 125 and 125%, respectively. SY supplementation resulted in lower liver Se concentration as Se supplementation increased (P < 0.05). CONCLUSIONS: Based on performance traits, the supplemental level of organic Se as SY in organic trace minerals supplement to support the maximal growth of broiler chicks is 0.133 mg Se/kg.
Assuntos
Ração Animal , Galinhas , Dieta/veterinária , Selênio/farmacologia , Oligoelementos/farmacologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Selênio/administração & dosagem , Selênio/farmacocinética , Oligoelementos/administração & dosagemRESUMO
With the aim of assessing health risk to shark consumers, cadmium, mercury, and selenium were measured in muscle of Sphyrna lewini from four coastal states (Baja California Sur, Sinaloa, Nayarit, and Colima) in western Mexico. According to length of specimens, three age modes were found: juveniles and neonates (the majority of the individuals), preadults and adults. Average concentrations (µg g-1 dry weight) in all the studied individuals followed the order cadmium (0.06), selenium (0.94), and mercury (1.56). The mean concentrations of cadmium and mercury increased significantly (pâ¯<â¯0.001) with mean length of specimens. Overall, hazard quotient and hazard index values were below one so there is no health risk to consumers. According to molar ratios of Hg and Se in the edible portion (muscle) of sharks, and depending on the areas of collection, individuals from Baja California Sur might not be beneficial to consumers.
Assuntos
Cádmio/análise , Mercúrio/análise , Músculos/química , Selênio/análise , Tubarões/metabolismo , Animais , Cádmio/farmacocinética , Humanos , Mercúrio/farmacocinética , México , Medição de Risco , Alimentos Marinhos/análise , Selênio/farmacocinética , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinéticaRESUMO
Selenium and mercury were evaluated in tissues and stomachs of the dolphinfish Coryphaena hippurus from two sites in the Southeastern Gulf of California. Hg levels were consistently low and exhibited the following patterns: muscle (0.14⯱â¯0.01⯵g/g wet weight) followed by kidney (0.12⯱â¯0.02⯵g/g), liver (0.11⯱â¯0.01⯵g/g), and gonads (0.04⯱â¯0.00⯵g/g). The maximum of Se was found in the kidney (5.60⯱â¯0.40⯵g/g) and the minimum in muscle (0.60⯱â¯0.01⯵g/g). All the Se:Hg molar ratios were between 3.7 and 697.1, with the minimum in muscle and the highest in gonads. The results indicate a contrasting behavior biomagnification of Hg and Se; smaller fish (<80â¯cm FL) did not exhibit biomagnification, in contrast with larger fish (>90â¯cm FL: 100% for Hg; 65% for Se). These results appear to be related to different feeding habits and availability of prey.
Assuntos
Conteúdo Gastrointestinal/química , Mercúrio/análise , Perciformes , Selênio/análise , Poluentes Químicos da Água/análise , Animais , Exposição Dietética/efeitos adversos , Feminino , Produtos Pesqueiros/análise , Contaminação de Alimentos/análise , Humanos , Rim/química , Masculino , Mercúrio/farmacocinética , México , Músculos/química , Oceano Pacífico , Medição de Risco , Selênio/farmacocinética , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinéticaRESUMO
With the aim of knowing the distribution of As, Hg, and Se in skipjack (Katsuwonus pelamis, Linnaeus, 1758) and yellowfin tuna (Thunnus albacares, Bonnaterre, 1788) from the Eastern Pacific, elemental concentrations were determined in the muscle and liver; As species were also analyzed in the stomach content. Additionally, health risk for consumers was assessed. For both tunas, levels of As and Se were significantly higher (p < 0.05) in the liver than in the muscle. In K. pelamis, Hg concentrations in the muscle were significantly higher (p < 0.05) than those in the liver. In T. albacares, As, Hg, and Se showed a trend to increase with fish dimensions. Arsenic extractability was better in the muscle than in the liver of both species; in K. pelamis, As species were better extracted than in T. albacares. In both tuna species, the most extractable arsenic was arsenobetaine (AsB) and a minor part was dimethylarsinic acid (DMA). The liver contained mainly AsB with some DMA and arsenocholine (AsC). Hazard indexes (HI) indicated no risk from Hg and Se intake through these tuna species. Considering the individual contribution to the HI, Hg contributed more (80 to 86%) than Se. In the context of health risk, none of the As and Hg values were above the permissible limits; however, two samples of T. albacares (9%) and three samples of K. pelamis (12%) had Se concentrations over the limits. If Hg and Se in the edible portion of tuna are considered under the approach of the HBVSe, tuna consumption is beneficial.
Assuntos
Arsênio/análise , Mercúrio/análise , Selênio/análise , Atum/metabolismo , Animais , Arsênio/farmacocinética , Fígado/química , Mercúrio/farmacocinética , Músculos/química , Oceano Pacífico , Alimentos Marinhos/análise , Selênio/farmacocinética , Especificidade da Espécie , Distribuição TecidualRESUMO
In the present study, the concentration of trace elements, total mercury (Hg) and selenium (Se) and mercury forms (MeHg, Hginorg and HgSe) in the vulnerable coastal dolphins Pontoporia blainvillei and Sotalia guianensis were appraised and compared, using metallothioneins (MT) and glutathione (GSH) as biomarkers for trace element exposure. The trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher Hg and Se concentrations than those found in muscle. Hg, MeHg and Hginorg molar concentrations showed a clear increase with Se molar concentrations in the liver of both dolphins, and Se concentrations were higher than those of Hg on a molar basis. Se plays a relevant role in the detoxification of MeHg in the hepatic tissue of both dolphins, forming Hg-Se amorphous crystals in liver. In contrast, MT were involved in the detoxification process of Hginorg in liver. GSH levels in P. blainvillei and S. guianensis muscle tissue suggest that these dolphins have different diving capacities. Muscle Hg concentrations were associated to this tripeptide, which protects dolphin cells against Hg stress.
Assuntos
Mergulho/fisiologia , Golfinhos/metabolismo , Glutationa/metabolismo , Mercúrio/análise , Metalotioneína/metabolismo , Selênio/análise , Poluentes Químicos da Água/análise , Animais , Biomarcadores/metabolismo , Brasil , Feminino , Inativação Metabólica , Fígado/metabolismo , Masculino , Mercúrio/farmacocinética , Compostos de Mercúrio/análise , Compostos de Mercúrio/farmacocinética , Compostos de Metilmercúrio/análise , Compostos de Metilmercúrio/farmacocinética , Músculos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Selênio/farmacocinética , Compostos de Selênio/análise , Compostos de Selênio/farmacocinética , Oligoelementos/análise , Oligoelementos/farmacocinética , Poluentes Químicos da Água/farmacocinéticaRESUMO
Mercury and selenium were assessed in the sailfish, Istiophorus platypterus, from the Eastern Pacific. Sixty-seven individuals were sampled, muscle, liver, kidney, gonads and the prey found in the stomach contents were isolated during fishing 2011-2013 tournaments. Hg exhibited the following pattern (µg g(-1) wet weight): liver (0.57 ± 0.07)>muscle (0.56 ± 0.04)>kidney (0.44 ± 0.08)>gonad (0.14 ± 0.01). The maximum concentration of Se was found in kidneys (14.1 ± 1.9 µg g(-1)), and the minimum in muscles (0.67 ± 0.03 µg g(-1)). High Se:Hg ratios were found for muscle (4.1 ± 0.3), kidney (132.4 ± 12.1), liver (54.0 ± 4.4) and gonads (88.2 ± 7.9); Hg:Se molar ratios were several orders of magnitude lower (muscle<0.4 and liver, kidney and gonad<0.03). Sailfish feed mainly on fishes and cephalopods with low Hg levels (<0.13 µg g(-1)), these results indicate biomagnification of Hg and Se. The muscle of I. platypterus should be consumed (according the provisional tolerable weekly intake) by people cautiously so as not to exceed the recommended intake of 215 g per week.
Assuntos
Conteúdo Gastrointestinal/química , Mercúrio/análise , Perciformes/metabolismo , Selênio/análise , Poluentes Químicos da Água/análise , Animais , Ingestão de Alimentos , Monitoramento Ambiental , Cadeia Alimentar , Humanos , Fígado/química , Mercúrio/farmacocinética , Músculos/química , Oceano Pacífico , Alimentos Marinhos/normas , Selênio/farmacocinética , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinéticaRESUMO
Mercury (Hg) and selenium (Se) concentrations were evaluated in a planktivorous fish and four size classes of organisms (FSCO), collected at an oligotrophic bay in the Southeastern Brazilian coast. No significant spatial differences between Hg and Se were found in the FSCO within the five sampling points in the bay. Hg and Se concentrations increased with successive increases in the size class of the analyzed plankton, i.e. approximately 3-and 2-fold, respectively, from microplankton to macroplankton. Hg and Se biomagnified throughout the planktonic food web. The smallest size class of organism, seston, composed of both biotic and abiotic portions, and fish showed the highest Hg concentrations. This indicates that Hg is not biomagnifying in the base of the bay food web. Selenium concentrations in fish were approximately 5.9 times higher than those in seston. Hg and Se concentrations in fish were approximately 3.5 and 14.6 times higher than those found in the plankton, respectively.
Assuntos
Monitoramento Ambiental/métodos , Peixes/metabolismo , Cadeia Alimentar , Mercúrio/análise , Plâncton/química , Selênio/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Mercúrio/farmacocinética , Selênio/farmacocinética , Clima Tropical , Poluentes Químicos da Água/farmacocinéticaRESUMO
The skin of bycaught Commerson's dolphins was tested for mercury (Hg) and selenium (Se) biomonitoring in Subantarctic environments. The correlation of levels detected in the skin with those found in internal tissues - lung, liver, kidney and muscle - was assessed to evaluate how skin represents internal Hg and Se distribution for monitoring purposes. Mercury in skin had a concentration range of 0.68-3.11 µg g(-1) dry weight (DW), while Se had a higher concentration range of 74.3-124.5 µg g(-1) DW. There was no significant correlation between selenium levels in any of the analyzed tissues. Thus, the skin selenium concentration did not reflect the tissular Se levels and did not provide information for biomonitoring. The lack of correlation is explained by the biological role of Se, provided that each tissue regulates Se levels according to physiological needs. However, the skin Hg level had significant positive correlation with the levels in internal tissues (ANOVA p<0.05), particularly with that of muscle (R(2)=0.79; ANOVA p=0.0008). Thus, this correlation permits the estimation of Hg content in muscle based on the multiplication of skin biopsy levels by a factor of 1.85. Mercury bioindication using skin biopsies is a non-lethal approach that allows screening of a large number of specimens with little disturbance and makes possible an adequate sampling strategy that produces statistically valid results in populations and study areas. The correlation between Hg levels in the skin and internal tissues supports the use of the epidermis of Commerson's dolphins for Hg biomonitoring in the waters of the Subantarctic, which is a poorly studied region regarding Hg levels, sources and processes.
Assuntos
Golfinhos/metabolismo , Monitoramento Ambiental/métodos , Mercúrio/análise , Selênio/análise , Pele/química , Poluentes Químicos da Água/análise , Animais , Argentina , Rim/química , Fígado/química , Mercúrio/farmacocinética , Músculos/química , Selênio/farmacocinética , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinéticaRESUMO
Top marine predators present high mercury concentrations in their tissues as consequence of biomagnification of the most toxic form of this metal, methylmercury (MeHg). The present study concerns mercury accumulation by Guiana dolphins (Sotalia guianensis), highlighting the selenium-mediated methylmercury detoxification process. Liver samples from 19 dolphins incidentally captured within Guanabara Bay (Rio de Janeiro State, Brazil) from 1994 to 2006 were analyzed for total mercury (THg), methylmercury (MeHg), total organic mercury (TOrgHg) and selenium (Se). X-ray microanalyses were also performed. The specimens, including from fetuses to 30-year-old dolphins, comprising 8 females and 11 males, presented high THg (0.53-132 µg/g wet wt.) and Se concentrations (0.17-74.8 µg/g wet wt.). Correlations between THg, MeHg, TOrgHg and Se were verified with age (p<0.05), as well as a high and positive correlation was observed between molar concentrations of Hg and Se (p<0.05). Negative correlations were observed between THg and the percentage of MeHg contribution to THg (p<0.05), which represents a consequence of the selenium-mediated methylmercury detoxification process. Accumulation of Se-Hg amorphous crystals in Kupffer Cells was demonstrated through ultra-structural analysis, which shows that Guiana dolphin is capable of carrying out the demethylation process via mercury selenide formation.
Assuntos
Células de Kupffer/metabolismo , Fígado/metabolismo , Mercúrio/metabolismo , Selênio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Golfinhos , Feminino , Masculino , Mercúrio/farmacocinética , Metilação , Microscopia Eletrônica de Transmissão , Selênio/farmacocinética , Poluentes Químicos da Água/farmacocinéticaRESUMO
UNLABELLED: Mushrooms have effective mechanisms to absorb and accumulate trace elements from substrates and, therefore could be used as a strategy to produce mineral-enriched food and nutritional supplements. This study aimed to enrich shiitake mushrooms with selenium (Se), an important dietary element in human health. Strains of Lentinula edodes (Berk.) were grown on artificial logs composed of eucalyptus sawdust, and were subjected to cold shock in water containing sodium selenite (Na(2)SeO(3) ) at concentrations of up to 1.28 mM. The content of Se in the mushrooms increased linearly with increasing amounts of Na(2)SeO(3) added to the cold water although above 0.96 mM, mushroom formation was inhibited. Concentrations greater than 17 mg Se 100/g of dried mushrooms were observed after treatment with 0.64 mM Na(2)SeO(3). Shiitake mushroom had a demonstrate potential to offer an effective and economical way to produce Se-enriched products and, the strategy of adding selenite in cold water, used in this study, showed promising once it does not interfere with mycelial growth. PRACTICAL APPLICATION: Selenium is an essential trace element for both human and animals and is required for the 21st amino acid, selenocysteine, which is used for the synthesis of about a dozen selenoenzymes. In this study, it is demonstrated that shiitake mushroom is a good Se accumulator and only one step during fructification was necessary to obtained enriched mushroom. Se enriched shiitake mushroom can be considered to be an excellent source of this element and used to consumption in different ways.