Efeitos de diferentes dietas sobre o metabolismo de lipídeos e de carboidratos em ratas normonutridas e desnutridas

A hipótese do fenótipo econômico propõe que a associação epidemiológica entre a restrição de crescimento intra-uterino e subseqüente desenvolvimento de Diabete Mellitus Tipo II (DM II) e a Síndrome Plurimetabólica resultam dos efeitos da má nutrição durante períodos críticos do crescimento e do desenvolvimento, que produz mudanças permanentes no metabolismo da glicose. Estas mudanças incluem capacidade reduzida para a secreção de insulina e resistência a insulina que, combinada com os efeitos da obesidade, do envelhecimento e da inatividade física, são fatores muito importantes no desenvolvimento do DM II. As ratas foram divididas em cinco grupos. Dois grupos receberam durante a gestação as seguintes dietas: grupo desnutrido e normonutrido: 7% e 25% de proteína e 10% de lipídio (óleo de soja), respectivamente. Após o nascimento as ratas continuaram com a dieta ofertada às mães até os 4 meses de idade. Grupo hipoprotéico e normoprotéico hiperlipídicos: 7% e 25% de proteína e 15% de lipídio (óleo de soja) durante a gestação e a lactação. Após o período lactacional as ratas dos grupos hiperlipídicos foram submetidas a uma dieta contendo 25% de proteína e 42% de lipídio (40 de banha de porco + 2% óleo de soja) até aos 8 meses de idade. O grupo que foi submetido a dieta comercial recebeu esta dieta durante a gestação e o período pós-natal. O objetivo do presente trabalho foi avaliar: I. Massa corporal; II. Relação tecido adiposo visceral/100 g massa corporal; III. Glicemia; IV. Concentração hepática de triglicerídeos; V. Captação de 2-deoxiglicose em fatias de músculo sóleo; VI. Teste de Sensibilidade à Insulina (TSI); VII. Teste de Tolerância à Glicose (TTG). Verificamos no presente trabalho que no grupo desnutrido: (i) a massa corporal foi menor em todas as idades avaliadas; (ii) a captação de 2-deoxiglicose em fatias de músculo foi 29,8% maior; (iii) no TTG a glicemia foi menor aos 30, 60 e 120 minutos após a injeção i.p. de glicose; (iiii) no TSI a glicemia foi menor aos 30 e 60 minutos após a injeção i.p. de insulina em relação ao grupo normonutrido. Verificamos, também, no presente trabalho que no grupo hipoprotéico hiperlipídico: (i) a relação do tecido adiposo total e visceral/100 g massa corporal foi maior nas duas idades estudadas; (ii) a captação de 2-deoxiglicose em fatias de músculo apresentou uma redução de 15,35%; (iii) a concentração plasmática de glicose foi 11,8% maior; (iiii) no TTG a glicemia foi maior, aos 30 e 60 minutos, após a injeção i.p. de glicose; (iiiii) a concentração hepática de triglicerídeos foi maior em relação ao grupo que foi submetido à dieta comercial Prévios estudos mostram que o insulto provocado pela restrição protéica durante o período fetal e lactacional aumenta a ação da insulina apesar de sua prejudicada secreção, mantendo assim uma tolerância normal à glicose. Mas, a ingestão de uma dieta hiperlipídica leva a um modesto prejuízo na ação periférica da insulina sem afetar a tolerância à glicose, em conseqüência da aumentada secreção de insulina. No entanto, a exposição crônica das duas intervenções dietéticas resulta em uma interação sinérgica, levando a um importante prejuízo na ação periférica da insulina em combinação com prejudicada resposta secretora de insulina, resultando em intolerância à glicose. Com estes resultados pode-se inferir que o genótipo econômico, a desnutrição durante a gestação e a lactação, uma dieta hiperlipídica e o estilo de vida sedentário são fatores que contribuem para o desenvolvimento da obesidade e conseqüentemente da resistência à insulina e do DM II.

Efeitos do exercício intermitente de alta intensidade e da suplemantação alimentar com carboidratos no metabolismo de glicídios em ratos treinados

Resumo não disponível

Efeito do trans-resveratrol sobre a longevidade e o metabolismo de glicogênio de Drosophila melanogaster em diferentes idades

O trans-resveratrol é uma fitoalexina natural encontrada em uvas, amoras, amendoim e muitas espécies de plantas. Em uvas o trans-resveratrol é responsável pela proteção natural contra doenças e sua concentração depende da origem geográfica, da variedade e dos métodos de fabricação do vinho; sendo considerado por muitos autores como um geroprotetor. O objetivo do presente trabalho foi verificar o efeito do transresveratrol na longevidade e no metabolismo de carboidratos (glicogênio, atividade e expressão da enzima glicogênio fosforilase - GFT) de Drosophila melanogaster em diferentes idades (0, 7, 14, 18 e 21 dias). Para a análise da longevidade espécimes de D. melanogaster com idade de 10 dias foram colocados em vidros contendo meio de cultura padrão acrescido de água ou dimetilsulfóxido (DMSO) 0,03%, ou trans-resveratrol nas concentrações de 1, 10 ou 20μM para ovoposição durante 24 horas, a prole recebeu os seus respectivos tratamentos durante toda a vida. Para as análises do metabolismo de glicogênio os espécimes de D. melanogaster foram colocados em meio de cultura padrão adicionado de água ou dimetilsulfóxido 0,03% (DMSO) ou ainda, trans-resveratrol na concentração de 1μM dissolvido em DMSO (0,03%) para ovoposição; seus ovos foram mantidos até a eclosão, durante a fase adulta os animais continuaram a receber os seus respectivos tratamentos até os pontos em que foram feitas as determinações bioquímicas e moleculares. Os resultados indicam que o tratamento com trans-resveratrol modulou o metabolismo de carboidratos em fêmeas e em machos de forma diferenciada; contudo, este composto não foi capaz de alterar a expressão gênica da GFT. Nas fêmeas tratadas com trans-resveratrol 1μM verificou-se um aumento de 127% na longevidade quando comparado ao grupo controle. Já nos machos tratados com trans-resveratrol 1μM observou-se um acréscimo de 50% na longevidade quando comparado ao grupo controle. Em ambos sexos tratados com Trans-resveratrol 10 e 20μM não houve aumento significativo da longevidade. Com base nos resultados podemos sugerir que o trans-resveratrol como outros antioxidantes descritos na literatura tem seus efeitos benéficos na menor dose administrada, podendo nas doses mais elevadas estar atuando como um pró-oxidante. Os resultados obtidos sugerem que o trans-resveratrol modula o metabolismo do glicogênio tanto em machos como em fêmeas e aumenta a longevidade do modelo experimental testado.

Avaliação das Opções Reais de Conversão e Abandono para Uma Mineradora de Minério de Ferro Sob Cenário de Stress

O mercado de minério de ferro tem passado por um período de stress nos últimos meses. O arrefecimento dos investimentos chineses em infraestrutura resultou em perspectivas negativas para a demanda dessa commodity. Paralelamente, a entrada em operação de novos projetos com volume de produção relevante aumentou a oferta desse produto no mercado. Essa conjuntura de fatores resultou na queda do preço do minério de ferro no mercado mundial e em um cenário de retornos reduzidos para as mineradoras. Nesse contexto, o objetivo do presente estudo é avaliar a flexibilidade gerencial, disponível aos administradores de mineradoras operacionais, de suspender ou fechar o empreendimento dependendo do preço do minério de ferro. Essas decisões serão estudadas através da Teoria das Opções Reais, onde a opção de conversão será aplicada na situação de suspensão e reabertura da mina e a opção de abandono será aplicada na situação do seu fechamento. O processo estocástico a ser seguido pelo preço do minério de ferro será o Movimento Geométrico Browniano, implementado através de um Modelo Binomial conforme proposto por Cox, Ross e Rubinstein (1979). O resultado do trabalho comprova o valor das opções reais estudadas e indica que essas opções reais têm maior valor em cenários de stress, quando o preço do minério de ferro está desvalorizado.

Morfologia, estrutura celular, metabolismo, nutrição e multiplicação de bactérias e leveduras

Unidade 2

Dos caminhos de água aos caminhos de ferro: a construção da hegemonia de Natal através das vias de transporte (1820-1920)

At a time of changes on the territory during the 19th century, the political and socioeconomic elites of the province and later State of Rio Grande do Norte evolved a discourse in order to justify the permanence of Natal as a city holding a status of capital. In this work we analyze the means employed by the ruling classes to impose their wish to raise Natal to an outstanding position among the existing cities by intervening on the territory during a period of one hundred years (1820-1920). During that time, which was characterized by changing commercial flows and technological development, the elites interventions were essentially directed to the implementation of modes of transportation, especially the railway. We try to understand the reinforcement of Natal as a capital city not only in political and administrative terms, but mainly in a commercial and symbolic manner, through the discourse and interventions undertaken by the local administrative elites, who stimulated the creation of a set of relations on the territory that also imprinted visible marks in the capital s urban fabric. These interventions were based upon the establishment of an infrastructure for exporting the State s production, firstly through and despite the Potengi River, and later on by the construction of railways. Although the project of Natal s hegemony had been outlined before the establishment of the railway network, in both cases the ultimate objective was to reinforce and develop the capital city as a commercial urban center to the detriment of other cities

A infecção por Leishmania infantum chagasi altera o metabolismo lipídico do hospedeiro

American visceral leishmaniasis (AVL), caused by Leishmania infantum chagasi (L.i.chagasi), stands as a public health problem in Brazil, with human and canine cases related in all states..Lipid metabolism can be modified in several status of infection. For example, experimental studies show that the cholesterol is necessary to internalization and replication of L.i.chagasi in macrophages through caveolar domains. Patients with AVL present low levels of cholesterol and a visible triglycerides increase. This work aimed to evaluate the lipid metabolism in several post-infection status by L.i.chagasi, including individuals with symptomatic infection (AVL), and asymptomatic. The levels of cholesterol, triglycerides, HDL and reactive C protein, were measured. Individuals with AVL were compared with individuals with assymptomatic infection and presented low levels of total cholesterol (128 ± 6.180 mg/dL vs. 158 ±5.733 mg/dL, p=0.0001), HDL (29 ± 1.746 mg/dL vs. 37 ± 1.647 mg/dL, p=0.0001), increased levels of triglycerides (149.5 mg/dL ± 12.72 vs. 78.00 ± 10.43 mg/dL, p=0.0095) and higher levels of reactive C protein (1.750± 0.4939 mg/dL vs. 0.40 ± 0.1707 mg/dL; p=0.0001). The expression of genes related to lipid metabolism, such as LXR-a, LXR-b, PPAR-a, PPAR-d, PPAR-g and APOE was evaluated by real time PCR. A reduction in the expression of those genes was found in the group of AVL patients corroborating the serum levels of the metabolites earlier quantified. Our findings suggest a modulation of metabolism of lipids, in the chronic phase of AVL, this could facilitate the survival of leishmania, due to the known reduction on the ability of macrophages in presenting antigens efficiently to the T cells due to the reduction in the cholesterol available, it results in a subversion of the host immunity.

O papel modulatório do ferro sobre a resposta imune na Leishmaniose Visceral

Iron is an essential element for many cellular functions, including the immune response against intracellular pathogens. In this study, we aimed evaluate the effect of iron on IRP2, IFN-γ, TNF-α, IL-6, IL-10, MIG and IP10 expression in PBMC and assess the effect of the spleen parasite load on the expression of these genes in the spleen of L. infantum naturally infected dogs. Blood sample from 7 DTH+ donor was collected and PBMC was obtained. The cells were cultivated in absence (iron chelator desferroximane, DFO 10 μM supplemented media) or in presence of iron (hemin 6 mM) for 1 h, followed by stimulation with Leishmania infatum antigen for 4 h. 44 dog spleen samples were obtained and parasite load in this organ was determinate by qPCR. Gene expression was analyzed by qPCR and cytokine production quantified by flow cytometry. In antigen stimulated cells, genes involved in immune response are significantly more expressed in presence of iron. T CD4+ and TCD8+ lymphocytes produces IFN-γ, TNF-α and IL-10 possibly in iron dependent pathway. Monocytes antigen stimulated reduced TNF-α, IL-6 and IL-10 production in presence of iron. We found spleen of infected dogs IRP2 expression increases according to parasite load in that organ, while an inverse profile was found for IFN-γ, TNF-α e IL-10 expression. These results suggest that T lymphocytes depends on iron to produce IFN-γ, TNF-α and IL-10, while iron seems to inhibit cytokine production in monocytes. So, we propose an immunoregulatory mechanism carried out by iron during L. infantum infection in humans and dogs

Estudo da adição do resíduo proveniente da extração de minério de ferro em argilas do Rio Grande do Norte

The mining industry is responsible for the generation of waste from their natural process of extraction. The mining impacts in urban areas are of special importance due to the high urban occupation, which are exacerbated due to the proximity of the mined areas and populated areas. Some solutions to wastedisposal have the potential to significantly reduce the environmental risks and liabilities, but represent higher costs in the stages of deployment and operation. The addition of mining waste as raw material in the development of commercial products reduces the environmental impacts, transforming the waste into a positive element in the generation of employment and income. This thesis studies the incorporation of waste iron ore in two clays, one from the ceramic industry of the City of Natal and the other from the ceramic industry of the Seridó Region, both in the State of Rio Grande do Norte, Brazil. Percentages of iron ore waste of 5%, 10% , 15%, 20%, 25% and 30% were used in the tested ceramic matrix. The two clays and the iron ore waste used as part of this investigation were characterized by X-ray diffraction tests, X-ray fluorescence tests, differential thermal analysis, thermogravimetric analysis and dilatometric analysis. The samples were sintered under temperatures of 850 °C, 950 °C and 1050°C at a heating rate of 5 °C/min with isotherms of two hours. The following tests were performed with the samples: linear shrinkage, water absorption, apparent porosity, apparent density, mass loss in fire and bending resistance in order to obtain their physical and mechanical properties. An amount of 5% of waste iron ore in the matrix clay at a temperature of 850 0C resulted in na increase of about 65% in the tensile strength of the clay samples from the Natal ceramic industry. A linear shrinkage of only 0.12% was observed for the samples, which indicates that the physical properties of the final product were not influenced by the addition of the waste

Interação competitiva do zinco e ferro após administração oral e venosa de zinco em crianças eutróficas

The aim of this study was to assess the acute and chronic effects of zinc in serum iron profile of children aged 6-9 years in relation to nutritional status and dietary intake. The study participants were 11 children regardless of sex, aged 6-9 years. They were selected from three public schools of the city of Natal, Brazil. Body mass index was used to assess nutritional status. In order to determine the patterns of childhood growth and ideal weight we used the standards of the World Health Organization. The dietary intake assessment was based on information from a three-day prospective food survey. The variables were energy intake, protein, lipids, carbohydrates, fiber, calcium, iron and zinc. All children underwent an intravenous administration of zinc (IVAZn) before and after oral administration of zinc (OAZn) (5 mg Zn / day) for three months. We measured serum iron, hematocrit, hemoglobin and total protein, before and after the use of oral zinc. The analysis of hematocrit, hemoglobin and total protein was performed using standard methods of clinical laboratory. Zinc levels and serum iron were measured by atomic absorption spectrophotometry. The project was evaluated and approved by the Ethics in Research Committee of Federal University of Rio Grande do Norte. Results: All children had normal weight. The consumption of energy, fat, fiber, calcium and iron were below recommended levels. However, the levels of protein and carbohydrates were high. Protein and zinc increased significantly after OAZn. Carbohydrate and protein were elevated in the blood. After OAZn, both protein and zinc increased, being statistically significant. Conclusion: The potential inhibitory effect of physiological or pharmacological doses of zinc on the profile of serum iron was observed in children with healthy weight and aged between 6 and 9 years. This negative effect of zinc did not affect the levels of hematocrit or hemoglobin, and therefore did not cause anemia. This was a multidisciplinary study, involving researchers from medicine, nutrition and pharmacy. This met the requirements of multidisciplinarity of the Post Graduate Program in Health Sciences of Federal University of Rio Grande do Norte.

Alterações no metabolismo de zinco relacionadas ao envelhecimento

Although many studies point to alterations in the organic concentrations of zinc in elderly patients, the mechanisms by which aging might cause changes in the metabolism of this nutrient remain unclear. Thus, we assessed the changes in plasma zinc, Zinc Binding Capacity to Plasma Protein (ZnBCPP) and Saturation Index (SI), comparing elderly individuals and young adults. The zinc analyses were performed by atomic absorption spectrophotometry. A statistically significant difference (p < 0.001) was found between the two groups, in relation to plasma zinc and SI, but the ZnBCPP did not differ between the younger and older subjects. In agreement with this result, it was shown in the young group that 76% (R2 = 0.760) of the ZnBCPP variations are explained by the variations in plasma zinc and SI. In the elderly group this measure decreased to 30.5% (R2 = 0.305). We conclude, therefore, that aging may be a factor associated to changes in control mechanisms and in zinc homeostasis, and could even alter ZnBCPP response patterns and other zinc-related indicators of nutritional status.

Suplementação oral de zinco pode diminuir o perfil sérico de ferro em crianças saudáveis

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Consequências da colectomia associada à hepatectomia no metabolismo hepático e na forma e função de hemácias em ratos

This study investigated the influence of partial colectomy associated with hepatectomy on the biodistribution of the 99mTc-phytate, on metabolic parameters, as well as labeling and morphology of red blood cells. Wistar rats were distributed into three groups (each with 6), nominated as colectomy, colectomy+hepatectomy and sham. In the 30th postoperative day all rats were injected with 99mTc-phytate 0.1mL i.v. (radioactivity 0.66 MBq). After 15 minutes, liver sample was harvested and weighed. Percentage radioactivity per gram of tissue (%ATI/g) was determined using an automatic gamma-counter. Serum AST, ALT, alkaline phosphatase and red blood cells labeling were determined. The liver %ATI/g and red blood cells labeling were lower in colectomy and colectomy+hepatectomy rats than in sham rats (p <0.05), and no difference was detected comparing the colectomy and colectomy+hepatectomy groups. Red blood cells morphology did not differ among groups. Serum levels of AST, ALT and alkaline fosfatase were significantly higher in colectomy+hepatectomy than in colectomy rats (p<0.001). Hepatectomy associated with colectomy lowered the uptake of radiopharmaceutical in liver and in red blood cells in rats, coinciding with changes in liver enzymatic activity

Influência do tratamento com ácido lipoico sobre o metabolismo ósseo e perfil antioxidante de mulheres na perimenopausa

Bone is a dynamic tissue that is in constant process of remodeling in response to mechanical stress and hormonal changes. This study aimed to understand the relationship between the biochemical changes, which women in the menopausal transition are subject to, and how the use of an alternative therapy with lipoic acid (LA) could influence these changes. The study of double-blind, was carried out in perimenopausal women that underwent a three month treatment with 600 mg of AL compared with another group that received placebo during the same period. This study showed that women had a waist circunference and body mass index above the values recommended by WHO (WC ≥ 80 cm; BMI > 25kg/m2). Associated with this, these women had increased concentrations of total cholesterol and triglycerides, and borderline LDL (Total Cholesterol > 200mg/dL; Triglycerides > 150mg/dL; LDL >130mg/dL). These changes were not affected by treatment with AL. There were no shifts in liver profile (ALT, AST and GGT), kidney profile (urea, creatinine, total protein and albumin), mineral profile (Total Calcium, Ionized Calcium, Phosphorus and Magnesium) as well in bone markers (osteocalcin, Total Alkaline Phosphatase and Tartrate Resistant Acid Phosphatase) after treatment with LA. The results of the oxidative profile showed that treatment with LA decreased GPx activity (p < 0,01), while for the TBARS, GSH and SOD activity there were no differences. With regard to SOD, this enzyme will submit to be high in the placebo group after 3 months of study (p<0,05). The expression of RANKL mRNA was reduced (p < 0,05) and of RANK increased (p <0.001), after treatment with LA, while the expression of IL-6 and TNF-ɑ genes were no changed. We conclude that women already in the perimenopause stage have changes in lipid profile and body composition that could induce shifts in oxidative and bone metabolism. However, LA treatment has provided an effective effect in the oxidative and bone profile since the earliest markers such as GPx activity and mRNA expression of RANKL, respectively, were reduced associated with no change in SOD activity. These results suggest a beneficial and protective effect of LA, indicating it potential as an alternative treatment to help the to prevent the complications associated with estrogen deficiency