17 resultados para pyruvate dehydrogenase complex

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Obesity is rampant in modern society and growth hormone (GH) could be useful as adjunct therapy to reduce the obesity-induced cardiovascular damage. To investigate GH effects on obesity, initially 32 male Wistar rats were divided into two groups (n = 16): control (C) was fed standard-chow and water and hyper-caloric (H) was fed hypercaloric chow and 30% sucrose in its drinking water. After 45 days, both C and H groups were divided into two subgroups (n = 8): C + PL was fed standard-chow, water and received saline subcutaneously; C + GH was fed standard-chow, water, and received 2 mg/kg/day GH subcutaneously; H + PL was fed hypercaloric diet, 30% sucrose in its drinking water, and received saline subcutaneously; and H + GH was fed hypercaloric diet, 30% sucrose in its drinking water, and received GH subcutaneously. After 75 days of total experimental period, H + PL rats were considered obese, having higher body weight, body mass index, Lee-index, and atherogenic index (AI) compared to C + PL. Obesity was accompanied by enhanced myocardial lipid hydroperoxide (LH) and lactate dehydrogenase (LDH), as well of depressed energy expenditure (RMR) and oxygen consumption(VO(2))/body weight. H + GH rats had higher fasting RMR, as well as lower AI and myocardial LH than H + PL. Comparing C + GH with C + PL, despite no effects on morphometric parameters, lipid profile, myocardial LH, and LDH activity, GH enhanced fed RMR and myocardial pyruvate dehydrogenase. In conclusion, the present study brought new insights into the GH effects on obesity related cardiovascular damage demonstrating, for the first time, that GH regulated cardiac metabolic pathways, enhanced energy expenditure and improved the lipid profile in obesity condition. Growth hormone in standard fed condition also offered promising therapeutic value enhancing pyruvate-dehydrogenase activity and glucose oxidation in cardiac tissue, thus optimizing myocardial energy metabolism.

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This study investigated the effects of growth hormone therapy on energy expenditure, lipid profile, oxidative stress and cardiac energy metabolism in aging and obesity conditions. Life expectancy is increasing in world population and with it, the incidence of public health problems such as obesity and cardiac alterations. Because growth hormone (GH) concentration is referred to be decreased in aging conditions, a question must be addressed: what is the effect of GH on aging related adverse changes? To investigate the effects of GH on cardiac energy metabolism and its association with calorimetric parameters, lipid profile and oxidative stress in aged and obese rats, initially 32 male Wistar rats were divided into 2 groups (n = 16), C: given standard-chow and water; H: given hypercaloric-chow and receiving 30 % sucrose in its drinking water. After 45 days, both C and H groups were divided into 2 subgroups (n = 8), C + PL: standard-chow, water, and receiving saline subcutaneously; C + GH: standard-chow, water, and receiving 2 mg/kg/day rhGH subcutaneously; H + PL: hypercaloric-chow, 30 % sucrose, receiving saline subcutaneously; H + GH: hypercaloric-chow, 30 % sucrose, receiving rhGH subcutaneously. After 30 days, C + GH and H + PL rats had higher body mass index, Lee-index, body fat content, percent-adiposity, serum triacylglycerol, cardiac lipid-hydroperoxide, and triacylglycerol than C + PL. Energy-expenditure (RMR)/body weight, oxygen consumption and fat-oxidation were higher in H + GH than in H + PL. LDL-cholesterol was highest in H + GH rats, whereas cardiac pyruvate-dehydrogenase and phosphofrutokinase were higher in H + GH and H + PL rats than in C + PL. In conclusion, the present study brought new insights on aging and obesity, demonstrating for the first time that GH therapy was harmful in aged and obesity conditions, impairing calorimetric parameters and lipid profile. GH was disadvantageous in control old rats, having undesirable effects on triacylglycerol accumulation and cardiac oxidative stress.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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We sought to explore the effects of doxorubicin on inflammatory profiles and energy metabolism in the hypothalamus of rats. To investigate these effects, we formed two groups: a control (C) group and a Doxorubicin (DOXO) group. Sixteen rats were randomly assigned to either the control (C) or DOXO groups. The hypothalamus was collected. The levels of interleukin (IL)-1β, IL-6, IL-10, TNF-α and energy metabolism (malate dehydrogenase, complex I and III activities) were analysed in the hypothalamus. The DOXO group exhibited a decreased body weight (p < 0.01). Hypothalamic malate dehydrogenase activity was reduced when compared with control (p < 0.05). In addition, pro-inflammatory cytokine levels were unchanged. Therefore, our results demonstrate that doxorubicin leads to an impairment of \hypothalamic energy metabolism, but do not affect the inflammatory pathway. Copyright © 2015 John Wiley & Sons, Ltd. Conflict of Interest Significance paragraph The hypothalamus is a central organ that regulates a great number of functions, such as food intake, temperature and energy expenditure, among others. Doxorubicin can lead to deep anorexia and metabolic chaos; thus, we observed the effect of this chemotherapeutic drug on the inflammation and metabolism in rats after the administration of doxorubicin in order to understand the central effect in the hypothalamus. Drug treatment by doxorubicin is used as a cancer therapy; however the use of this drug may cause harmful alterations to the metabolism. Thus, further investigations are needed on the impact of drug therapy over the long term.

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Replicative life span in Saccharomyces cerevisiae is increased by glucose (G1c) limitation [ calorie restriction (CR)] and by augmented NAD(+). Increased survival promoted by CR was attributed previously to the NAD(+)-dependent histone deacetylase activity of sirtuin family protein Sir2p but not to changes in redox state. Here we show that strains defective in NAD(+) synthesis and salvage pathways (pnc1 Delta, npt1 Delta, and bna6 Delta) exhibit decreased oxygen consumption and increased mitochondrial H2O2 release, reversed over time by CR. These null mutant strains also present decreased chronological longevity in a manner rescued by CR. Furthermore, we observed that changes in mitochondrial H2O2 release alter cellular redox state, as attested by measurements of total, oxidized, and reduced glutathione. Surprisingly, our results indicate that matrix-soluble dihydrolipoyl-dehydrogenases are an important source of CR-preventable mitochondrial reactive oxygen species (ROS). Indeed, deletion of the LPD1 gene prevented oxidative stress in npt1 Delta and bna6 Delta mutants. Furthermore, pyruvate and alpha-ketoglutarate, substrates for dihydrolipoyl dehydrogenase-containing enzymes, promoted pronounced reactive oxygen release in permeabilized wild-type mitochondria. Altogether, these results substantiate the concept that mitochondrial ROS can be limited by caloric restriction and play an important role in S. cerevisiae senescence. Furthermore, these findings uncover dihydrolipoyl dehydrogenase as an important and novel source of ROS leading to life span limitation.

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Submandibular glands of male rats were homogenized with 33 mM sodium potassium phosphate buffer, pH 6.5, containing 1 mM MgCl2 and 0.1 mM DTT and purified with ammonium sulphate, phosphocellulose chromatography, eluted with KC1 0.5 M, followed by Blue Sepharose CL-6B chromatography, eluted with NADH 0.5 mM. The enzyme kepts stable for 60 days when stored at -15-degrees-C in 33 mM phosphate buffer. In other experiment the enzyme was purified by oxamate-agarose chromatography from a crude extract of submandibular gland and the results obtained were better than by phosphocellulose and Sepharose CL-6B chromatography. The Km values for pyruvate. NADH, lactate and NAD+ were established. Sodium oxamate at 0.1 and 0.9 mM concentrations inhibited the LDH activity by 40 and 85%, respectively (competitive); with sodium oxalate the inhibition was of 30% (uncompetitive) and with 3-acetyl pyridine adenine dinucleotide was 80%.