RESUMO
Limited information exists on the use of zinc-l-selenomethionine (Zn-L-SeMet) in broiler diets and its effects on the growth performance, body temperature, mortality rates, blood profile, and gene expression, especially when animals are reared under cyclic heat stress conditions. This study aimed to investigate the impact of Zn-L-SeMet in broiler diets from 1 to 42 days of age reared under cyclic heat stress and its effects on growth performance, cloacal temperatures, mortality rate, blood parameters, and insulin-like growth factor 1 (IGF-1) and growth hormone receptor (GHR) gene expression in the breast muscle. A total of 1000 male Cobb 500® broiler chicks were randomly assigned to five treatments: 0, 0.15, 0.23, 0.47, and 1.30 mg/kg of Zn-L-SeMet. Each treatment consisted of 10 replicates with 20 birds each. No statistically significant differences in growth performance were observed from 1 to 21 days of age (P > 0.05). However, from 1 to 42 days, feed intake (FI) and feed conversion ratio (FCR) decreased linearly (P < 0.05). Cloacal temperatures showed no significant effects (P > 0.05), while overall mortality rate exhibited a quadratic response (P < 0.05), with the optimal inclusion level predicted to reduce broiler mortality at 0.71 mg/kg. Triglyceride (TRG) levels increased with 0.97 mg/kg (P < 0.05), and gama-glutamil transferase (GGT) levels decreased with the inclusion of 1.19 mg/kg (P < 0.05). No significant effects on IGF-1 and GHR gene expression were found (P > 0.05). In conclusion, the inclusion of 1.30 mg/kg of Zn-L-SeMet in diets of heat-stressed broilers improved growth performance from 1 to 42 days of age. An inclusion of 0.71 mg/kg reduced mortality rate, while 0.97 mg and 1.19 mg increased and reduced TRG and GGT levels, respectively.
Assuntos
Selenometionina , Zinco , Animais , Masculino , Selenometionina/metabolismo , Galinhas , Suplementos Nutricionais , Fator de Crescimento Insulin-Like I/metabolismo , Dieta/veterinária , Resposta ao Choque Térmico , Ração Animal/análiseRESUMO
A successful mushroom enrichment process must produce foods that have compounds potentially absorbed by the human body. In this study, Pleurotus ostreatus and Pleurotus djamor mushrooms were grown on organic substrate supplemented with different Se(IV) and Se(VI) concentrations, and evaluated in the following features: Fruiting bodies morphology; Se uptake and accumulation; Distribution of proteins and protein-bound Se; Se species identification on enzymatic extracts; Se bioaccessibility; and Distribution of bioaccessible protein-bound Se. Pleurotus djamor grown on Se(IV)-supplemented substrate showed the greatest potential to uptake and accumulate Se. For Se species screening, selenomethionine was identified in white oyster mushroom, while selenomethionine, selenocystine, and Se-methylselenocysteine in pink oyster mushrooms. In soluble fractions from in vitro gastrointestinal digestion assays, Se showed high bioaccessibility (>94%). Lastly, bioaccessible Se species were found to be mainly associated to LMW (<17 kDa) in Pleurotus ostreatus (74%) and Pleurotus djamor (68%) grown on Se(IV)-supplemented substrates.
Assuntos
Agaricales , Pleurotus , Agaricales/química , Suplementos Nutricionais , Humanos , Pleurotus/química , Selenometionina/metabolismoRESUMO
Selenium is an essential element in human and animal metabolism integrated into the catalytic site of glutathione peroxidase (GPX1), an antioxidant enzyme that protects cells from damage caused by reactive oxygen species (ROS). Oxidative stress refers the imbalance between ROS and antioxidant defense systems. It generates alterations of DNA, proteins and lipid peroxidation. The imbalance occurs particularly during ischemia and lack of postmortem perfusion. This mechanism is of relevance in transplant organs, affecting their survival. The aim of this research is to evaluate the effect of seleno-methionine (SeMet) as a protective agent against postmortem ischemia injury in transplant organs. Wistar rats were orally administered with SeMet. After sacrifice, liver, heart and kidney samples were collected at different postmortem intervals (PMIs). SeMet administration produced a significant increase of Se concentration in the liver (65%, p < 0.001), heart (40%, p < 0.01) and kidneys (45%, p < 0.05). Levels of the oxidative stress marker malondialdehyde (MDA) decreased significantly compared to control in the heart (0.21 ± 0.04 vs. 0.12 ± 0.02 mmol g-1) and kidneys (0.41 ± 0.02 vs. 0.24 ± 0.03 mmol g-1) in a PMI of 1-12 h (p < 0.01). After SeMet administration for 21 days, a significant increase in GPX1 activity was observed in the liver (80%, p < 0.001), kidneys (74%, p < 0.01) and heart (35%, p < 0.05). SeMet administration to rats significantly decreased the oxidative stress in the heart, liver and kidneys of rats generated by postmortem ischemia.
Assuntos
Coração , Isquemia/metabolismo , Rim/metabolismo , Fígado/metabolismo , Selenometionina/metabolismo , Administração Oral , Animais , Feminino , Estresse Oxidativo , Ratos , Ratos Wistar , Selenometionina/administração & dosagem , Selenometionina/análiseRESUMO
The aim of the present study was to verify the effect of selenomethionine (SM) supplementation in the diet of chickens on performance, carcass yield, apparent retention, meat quality, and selenium (Se) deposition in tissues. In the first experiment, 2,100 day-old male chicks from the Hubbard Flex strain were randomly distributed in 84 plots with 12 treatments and 7 replicates. The treatments consisted of SM (1,600 ppm) supplementation at levels of 0.3 and 0.5 ppm in substitution of sodium selenite (45.7%) in different preslaughter phases. In the second experiment, 224 day-old male chicks from Hubbard Flex strain were randomly distributed in 28 metabolic cages. Poultry were distributed in 4 treatments with 7 replicates (8 poultry) in the experimental period from 1 to 21 D and experimental plot with 4 poultry aged from 22 to 42 D. Treatments consisted of 4 SM addition levels (0.3, 0.4, 0.5, and 0.6 ppm). In both experiments, the performance (1 to 21 and 1 to 42 D), carcass yield and cuts, apparent retention of Se (33 to 35 D), physical and chemical characteristics of the breast meat were evaluated: objective color, drip loss (DL), cooking loss (CL), pH, peroxide value, and Se deposition in tissues. In experiment I, it was found that SM at 0.3 ppm improved the weight gain and feed conversion of 1 to 42 D. The use of SM at 0.5 ppm resulted in lower DL and CL. The highest Se deposition in muscles was obtained using the SM at 0.5 ppm of 1 to 42 D. Using the SM at 0.5 ppm, only in the last week there was a deposition similar to the use of SM at 0.3 ppm of 1 to 42 D. In experiment II, it can be observed that increased SM levels provided lower DL and lower pH values. Se deposition in tissues of broiler chickens increased linearly at the SM level from 0.3 to 0.6 ppm.
Assuntos
Galinhas/fisiologia , Carne/análise , Selênio/metabolismo , Selenometionina/metabolismo , Fatores Etários , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Masculino , Distribuição Aleatória , Selenometionina/administração & dosagem , Distribuição TecidualRESUMO
The distribution and speciation of selenium (Se) in freshwater fish (muscle and liver tissue) from lakes in Argentina was investigated. Three introduced species, brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis), and one native species, creole perch (Percichthys trucha), were investigated. Values for total selenium in muscle ranged from 0.66 to 1.61 µg/g, while in the liver, concentrations were much higher, from 4.46 to 73.71 µg/g on a dry matter basis. Separation of soluble Se species (SeCys(2), selenomethionine (SeMet), SeMeSeCys, selenite and selenate) was achieved by ion exchange chromatography and detection was performed by inductively coupled plasma-mass spectrometry. The results showed that in fish muscle, from 47 to 55 % of selenium was soluble and the only Se species identified was SeMet, which represented around 80 % of soluble Se, while in the liver, the amount of soluble Se ranged from 61 to 76 % and the percentage of species identified (SeMet and SeCys(2)) was much lower and ranged from 8 to 17 % of soluble Se.
Assuntos
Fígado/metabolismo , Músculos/metabolismo , Percas , Selênio/metabolismo , Truta , Animais , Argentina , Cromatografia por Troca Iônica , Monitoramento Ambiental/métodos , Gorduras/metabolismo , Água Doce , Lagos , Percas/metabolismo , Reprodutibilidade dos Testes , Selenometionina/análise , Selenometionina/metabolismo , Selenito de Sódio/análise , Selenito de Sódio/metabolismo , Solubilidade , Truta/metabolismoRESUMO
Xanthomonas axonopodis pv. citri YaeQ (XAC2396) is a member of a family of bacterial proteins conserved in several Gram-negative pathogens. Here, the cloning, expression, purification and crystallization of the 182-residue (20.6 kDa) YaeQ protein are described. Recombinant YaeQ containing selenomethionine was crystallized in space group P2(1) and crystals diffracted to 1.9 A resolution at a synchrotron source. The unit-cell parameters are a = 39.75, b = 91.88, c = 48.03 A, beta = 108.37 degrees. The calculated Matthews coefficient suggests the presence of two YaeQ molecules in the asymmetric unit. Initial experimental phases were calculated by the multiple-wavelength anomalous dispersion technique and an interpretable electron-density map was obtained.
Assuntos
Proteínas de Bactérias/química , Xanthomonas/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Cristalização , Cristalografia por Raios X , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Selenometionina/química , Selenometionina/metabolismo , Xanthomonas/genética , Xanthomonas/metabolismoRESUMO
Two different approaches towards the study of protein turnover in skeletal muscle were made. The first approach involved the injection of 75Se Selenomethionine into rats and the subsequent measurement of the whole body decay rate of the 75Se activity in a 4 pi liquid scintillation counter. By this means it was hoped that the whole body decay curve could be analysed into exponentials representative of 'fast' (visceral protein) and 'slow' (muscle protein) pools. This proved not to be feasible. The special difficulties resulting from the use of 75Se-labelled amino acids are discussed. As a second approach a search was made for a technique for labelling muscle proteins so that radioactivity decay rates could be used directly to calculate rates of synthesis and catabolism without the usual errors arising from isotope reutilisation. 75Se selenomethionine, 14C-6 arginine, 14C-Na2 CO3 and 14C-1 glutamate were investigated. 14C-Na2 CO3 proved to be suitable especially if the decay rates of separate and glutamate isolated from muscle proteins labelled with 14C Na2 CO3 are measured. The lack of reutilisation of label is discussed in terms of the metabolic activity of the carboxyl groups of these dicarboxylic amino acids. The effects of acute deprivation of calories and protein on synthesis and catabolism of muscle and liver protein was measured in rats, using the 14C-Na2 CO3 labelling method. The synthesis rates for muscle proteins, 0.25 and 0.097 days-1 for sarcoplasmic and myofibrillar proteins respectively are the fastest reported in the literature. The total protein synthesised and catabolised in muscle sarcoplasmic and myofibrillar fractions was calculated and compared with liver. The protein free diet caused a reduction in synthesis rates in liver and muscle protein with no change in the distribution pattern between the tissues. The starved rats showed a shift in the distribution pattern of synthesis towards liver and a concomitant shift towards muscle in catabolism. The results are discussed in terms of the mobility and therefore importance of muscle protein metabolism in the economy of the whole animal (AU)