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Mass Spectroscopic Identification and Quantification of Protein CarbonylsUgur, Zafer 08 August 2012 (has links)
It is well established that free radical mediated oxidative stress plays a critical role in aging and age-related diseases. Among the post-translational protein modifications, carbonylation has attracted a great deal of attention due to its irreversible and irreparable nature. Despite the fact that protein carbonylation is associated with a series of physiological and pathological processes, there are still issues to be clarified such as why certain proteins are more vulnerable to modification, what are the locations of the protein modifications, and how does the nature of the oxidant affect the preferred site of modification. In this study, we will seek an answer to these questions and examine the global effect of oxidative stress on protein abundance. The study embraces three distinct specific aims. In the first, methods are developed for identifying sites of protein carbonylation. In the second specific aim, these methods are used to identify carbonylaytion sites in model proteins subjected to chemical oxidants. In the third aim, the focus is on a model organism, C. elegans, subjected to paraquat-induced oxidative stress. This is exploratory work and mass spectrometry is used to assess the impact of oxidative stress on the mitochondrial proteome.
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Vliv opioidů na redoxní stav potkaního myokardu / The effect of opioids on the redox state of rat myocardiumJandová, Gabriela January 2014 (has links)
The aim of this work was to study the expression of proteins involved in reactions in which harmful free radicals are degraded in an organism. was observed difference between the expression of selected myocardial proteins in non-influenced animals, animals who were treated with low dosage of morphine (0.1 mg/kg/day or 1 mg/kg/day), and animals administered high dosage of morphine (10 mg/kg/day). Low dosages were administered for 28 days and high dosage for 10 days. In addition, the effect of abstinence lasting one week was assessed after cessation of morphine administration (1 mg/kg/day). Morphine at low dosage (0.1 mg/kg/day) increased levels of glutathion peroxidase-1/2, which may be considered as one of the possible consequences of the ongoing oxidative stress. There were no significant differences in glutathion peroxidase-6 expression. Next aim of this work was to study the expression of antioxidant enzymes. These experiments were carried out on myocardial preparations from the animals treated with a constant dosage of morphine (10 mg/kg/day) for 10 days. Samples from these animals were used for measuring the total antioxidant capacity of the left and right ventricles. These samples were also used for determination of concentration of the oxidative stress marker 8-isoprostane. We also aimed to...
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Regulation of oxidative stress and inflammation in ischemia/reperfusion-induced acute kidney injuryWang, Pengqi 06 April 2016 (has links)
Renal ischemia/reperfusion (I/R) is a main cause of acute kidney injury (AKI) and delayed graft function after renal transplantation. Previous studies in human and experimental models have identified that inflammation and oxidative stress are two key players in renal I/R injury. However, the underlying mechanisms remain speculative. The overall objective of the study was to investigate the biochemical and molecular mechanisms of I/R-induced renal injury and the effect of tyrosol supplementation on I/R-induced kidney oxidative stress damage.
In the present study, renal I/R was induced in Sprague-Dawley rats and in a human kidney proximal tubular cell line. A significantly elevated expression of pro-inflammatory cytokine expression (MCP-1, IL-6) was observed. There was a significant decrease in mRNA and protein levels of two hydrogen sulphide (H2S)-producing enzymes, CBS and CSE, with a concomitant reduction of glutathione and H2S production. In the cell culture model, hypoxia–reoxygenation of proximal tubular cells led to a decrease in CBS and CSE expression and an increase in pro-inflammatory cytokine expression. Supplementation of glutathione or H2S donor (NaHS) effectively abolished cytokine expression in tubular cells.
Experiments were conducted to detect oxidative stress markers. It was demonstrated that there was a significant increase in peroxynitrite formation and lipid peroxidation in the kidney after I/R insult, which might be caused by the elevation in nitric oxide (NO) metabolites and inducible nitric oxide synthase (iNOS). Administration of tyrosol, a natural phenolic compound, reduced peroxynitrite formation, lipid peroxidation and the level of NO metabolites via inhibiting NF-B activation and iNOS expression. Tyrosol treatment improved kidney function and had a protective effect against I/R-induced AKI.
The present study has clearly demonstrated that (1) there is a reduction of H2S production via inhibition of CBS and CSE expression, which contributes to increased pro-inflammatory cytokine expression in the kidney and in tubular cells upon I/R insult; (2) restoration of endogenous H2S production would be of therapeutic value in regulating inflammatory response in I/R-induced kidney injury; (3) tyrosol treatment has a beneficial effect against renal I/R-induced oxidative stress, in part, through its inhibition on NF-B activation and iNOS-mediated NO production. / May 2016
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Reduced Nrf2 expression mediates the decline in neural stem cell function during a critical middle-age periodCorenblum, Mandi J., Ray, Sneha, Remley, Quentin W., Long, Min, Harder, Bryan, Zhang, Donna D., Barnes, Carol A., Madhavan, Lalitha 08 1900 (has links)
Although it is known that the regenerative function of neural stem/progenitor cells (NSPCs) declines with age, causal mechanisms underlying this phenomenon are not understood. Here, we systematically analyze subventricular zone (SVZ) NSPCs, in various groups of rats across the aging spectrum, using in vitro and in vivo histological and behavioral techniques. These studies indicate that although NSPC function continuously declines with advancing age, there is a critical time period during middle age (13-15 months) when a striking reduction in NSPC survival and regeneration (proliferation and neuronal differentiation) occurs. The studies also indicate that this specific temporal pattern of NSPC deterioration is functionally relevant at a behavioral level and correlates with the decreasing expression of the redox-sensitive transcription factor, Nrf2, in the NSPCs. When Nrf2 expression was suppressed in 'young' NSPCs, using short interfering RNAs, the survival and regeneration of the NSPCs was significantly compromised and mirrored 'old' NSPCs. Conversely, Nrf2 overexpression in 'old' NSPCs rendered them similar to 'young' NSPCs, and they showed increased survival and regeneration. Furthermore, examination of newborn Nrf2 knockout (Nrf2-/-) mice revealed a lower number of SVZ NSPCs in these animals, when compared to wild-type controls. In addition, the proliferative and neurogenic potential of the NSPCs was also compromised in the Nrf2-/- mice. These results identify a novel regulatory role for Nrf2 in NSPC function during aging and have important implications for developing NSPC-based strategies to support healthy aging and to treat age-related neurodegenerative disorders.
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Insight into oxidative stress mediated by nitric oxide synthase (NOS) isoforms in atherosclerosisPadmapriya, Ponnuswamy January 2008 (has links) (PDF)
The principle product of each NOS is nitric oxide. However, under conditions of substrate and cofactor deficiency the enzymes directly catalyze superoxide formation. Considering this alternative chemistry of each NOS, the effects of each single enzyme on key events of atherosclerosis are difficult to predict. Here, we evaluate nitric oxide and superoxide production by all three NOS isoforms in atherosclerosis. ESR measurements of circulating and vascular wall nitric oxide production showed significantly reduced nitric oxide levels in apoE/eNOS double knockout (dko) and apoE/iNOS dko animals but not in apoE/nNOS dko animals suggesting that eNOS and iNOS majorly contribute to vascular nitric oxide production in atherosclerosis. Pharmacological inhibition and genetic deletion of eNOS and iNOS reduced vascular superoxide production suggesting that eNOS and iNOS are uncoupled in atherosclerotic vessels. Though genetic deletion of nNOS did not alter superoxide production, acute inhibition of nNOS showed that nNOS contributes significantly to superoxide production. In conclusion, uncoupling of eNOS occurs in apoE ko atherosclerosis but eNOS mediated superoxide production does not outweigh the protective effects of eNOS mediated nitric oxide production. We show that although nNOS is not a major contributor of the vascular nitric oxide formation, it prevents atherosclerosis development. Acute inhibition of nNOS showed a significant reduction of superoxide formation suggesting that nNOS is uncoupled. The exact mechanism of action of nNOS in atheroprotection is yet to be elucidated. Genetic deletion of iNOS reduced NADPH oxidase activity. Thus, iNOS has both direct and indirect proatherosclerotic effects, as it directly generates both nitric oxide and superoxide simultaneously resulting in peroxynitrite formation and indirectly modulates NADPH oxidase activity. We hypothesize that eNOS is coupled in the disease free regions of the vessel and contributes to nitric oxide generation whereas in the diseased region of the vessel it is uncoupled to produce superoxide (Figure 16). nNOS expressed in the smooth muscle cells of the plaque contributes to the local superoxide generation. iNOS expressed in smooth muscle cells and leukocytes of the plaque generates superoxide and nitric oxide simultaneously to produce the strong oxidant peroxynitrite. / Stickstoffmonoxid (NO) ist das prinzipielle Produkt aller Stickstoffmonoxid-Synthasen (NOS). Im Falle eines Mangels an Substrat (L-arginin) und Kofaktoren (Tetrahydrobiopterin, BH4) katalysieren die NOS-Enzyme direkt Superoxid (O2-). Diese Veränderung in der Radikalproduktion wird auch als Entkopplung der NOS bezeichnet. Die alternative Produktion von NO oder O2- durch die NOS bedingen, dass eine Voraussage über die Schlüsselfunktion der einzelnen Enzyme in der Entstehung der Atherosklerose schwierig ist. In unserer Studie evaluieren wir die Produktion von NO sowie O2- in atherosklerotischen Läsionen von apoE ko Mäusen und apoE/NOS doppel knockout (dko) Mäusen denen jeweils eine NOS-Isoform fehlt. Elektronen Spin Resonanz (ESR) Messungen konnten eine signifikante Reduktion sowohl des zirkulierenden, als auch der Gefäßwand eigenen Produktion von NO in apoE/eNOS dko und apoE/iNOS dko Mäusen zeigen, nicht jedoch in apoE/nNOS dko Mäusen. Dies lässt darauf schließen, dass eNOS und iNOS den hauptsächlichen Anteil der vaskulären NO-Produktion in atherosklerotischen Läsionen bewerkstelligen. Die pharmakologische Inhibierung wie auch die genetische Deletion von eNOS und iNOS führten ebenfalls zu einer reduzierten vaskulären O2- produktion, was die partielle Entkopplung beider Enzyme in atherosklerotisch veränderten Gefäßen nahe legt. Obwohl die chronische genetische Deletion von nNOS in apoE/nNOS dko die O2- Produktion nicht verändert, zeigte sich bei der akuten pharmakologischen Inhibierung von nNOS (durch L-NAANG) eine maßgebliche Beteiligung von nNOS an der O2- produktion in apoE ko Mäusen. Schlussfolgernd lässt sich sagen, dass in atherosklerotischen Gefäßen von apoE ko Tieren eine Entkopplung von eNOS statt findet, diese jedoch zu keinem Ausgleich der protektiven Effekte der eNOS vermittelten NO-Produktion führt. Unsere Ergebnisse in apoE/nNOS dko Mäusen zeigen eine atheroprotektive Rolle der nNOS, die sich nicht allein durch eine lokale, vaskuläre NO-Produktion durch das Enzym erklären lässt. Wir postulieren weitere systemisch atheroprotektive Eigenschaften der nNOS. Die signifikante Reduktion der Superoxidproduktion durch eine akute Inhibierung der nNOS weist auf eine Entkopplung der nNOS hin. Der exakte Wirkungsmechansimus von nNOS in der Atheroskleroseprävention ist weiterhin noch zu eruieren. Die genetische Deletion von iNOS führt zu einer reduzierten Aktivität der NADPH-Oxidase. Demnach sind für iNOS direkte sowie indirekte atherosklerosefördernde Effekte anzunehmen, da sie auf direktem Wege gleichzeitig NO und O2- produziert, was in einer Peroxynitritbildung resultiert. Wir stellen die Hypothese auf, dass eNOS in den läsionsfreien Gefäßregionen gekoppelt ist und dort seine atheroprotektiven Effekte durch die NO-Produktion vermittelt, während die eNOS in atherosklerotischen Läsionen entkoppelt vorliegt und hier O2- produziert (Fig. 16). iNOS, welches vor allem in den Plaques, in glatten Muskelzellen und Leukozyten zu finden ist, produziert gleichzeitig hohe Konzentrationen von O2- und NO, die als gemeinsames Endprodukt das stark oxidierende Peroxynitrit ergeben und die von uns dokumentierte proatherosklerotische Wirkung der iNOS vermittelt.
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Potencial antioxidante, fotoprotetor e antiglicante de frutos alimentícios não convencionais para utilização na indústria alimentícia, cosmética e farmacêutica /Martins, Gustavo Rafagnin. January 2017 (has links)
Orientador: Regildo Marcio Gonçalves da Silva / Banca: Dario Abel Palmieri / Banca: Valter Henrique Marinho dos Santos / Resumo: O estresse oxidativo está correlacionado ao aparecimento de doenças, e pode ser intensificado devido à exposição a fatores ambientais, como estresse, abuso de drogas, radiação solar, poluição entre outros. Estudos com vegetais têm demonstrado que os mesmos podem conter compostos antioxidantes passíveis de remediar ou prevenir tais complicações. Nesse contexto o presente trabalho avaliou a atividade antioxidante, antiglicante, fotoprotetora e verificou-se a presença de compostos polifenólicos dos extratos aquoso, etanólico e hidroalcoólico de frutos de Chrysophyllum cainito L, Hancornia speciosa Gomes. e P. glomerata Berg., além disso foram produzidas e analisadas geleias desses frutos. Compostos fenólicos foram determinados por técnicas espectrofotométrica e HPLC (High performance liquid cromatography). Foi verificada a presença de compostos fenólicos, incluindo flavonoides, para todos os de frutos avaliados, com destaque para os extratos de C. cainito (casca), que apresentou os maiores valores com o extrato hidroetanólico dessa espécie. Quanto a atividade antioxidante, novamenta a espécie de C. cainito obteve os mais valores entre os resultados para os diferentes testes realizados, sequestro do radical livre DPPH, potencial redutor de ferro (FRAP - ferric reducing antioxidant power), inibição da peroxidação lipídica (TBARS - thiobarbituric acid reactive substances), e sequestro do NO, entretanto os demais extratos avaliados para as outras espécies, H. speciosa e P. glomerata... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Oxidative stress is correlated with the onset of disease, and can be intensified due to exposure to environmental factors such as stress, drug abuse, solar radiation, pollution, among others. Studies with vegetables have shown that they may contain antioxidant compounds likely to remedy or prevent such complications. In this context, the present work evaluated antioxidant, antiglican and photoprotective activity and verified the presence of polyphenolic compounds of the aqueous, ethanolic and hydroalcoholic extracts of fruits of Chrysophyllum cainito L., Hancornia speciosa Gomes. and P. glomerata Berg. in addition, jellies of these fruits were produced and analyzed. Phenolic compounds were determined by spectrophotometric techniques and HPLC (High performance liquid chromatography). It was verified the presence of phenolic compounds, including flavonoids, for all evaluated fruits, especially the extracts of C. cainito (peel), which presented the highest values with the hydroethanolic extract of this species. As for the antioxidant activity, again the C. cainito species obtained the highest values among the results for the different tests performed, DPPH free radical sequestration, ferric reducing antioxidant power (FRAP), inhibition of lipid peroxidation (TBARS - thiobarbituric acid reactive substances), and NO scavenging. However, the other extracts evaluated for the other fruit species, H. speciosa and P. glomerata also obtained significant results. These results Indicate antioxidant potential for the fruits of these species tested and that are possibly related to the presence of phenolic compounds. Only the hydroethanolic (70%) extract of P. glomerata indicated antiglication activity at the concentration of 10mg.mL-1. As for the jellies produced, the C. cainito jelly also obtained prominent results for both nutritional and functional constituents, but the P. glomerata one presented... / Mestre
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Approaches for raising the level of FOXO3a in animal cellsUnknown Date (has links)
The turtle is a unique model of anoxic survival. The turtle's brain can tolerate total oxygen deprivation for hours to days as well as prevent high levels of mitochondrial-derived free radicals upon re-oxygenation. Because of its ability to prevent elevated free radical generation, the turtle has also become recognized as a model of exceptional longevity. We are employing the turtle model for an investigation into the regulation of a key antioxidant enzyme system - methionine sulfoxide reductases (Msrs), primarily MsrA and MsrB. The Msr system is capable of reversing oxidation of methionines in proteins and Msr subtypes have been implicated in protecting tissues against oxidative stress, as well as, enhancing the longevity of organisms from yeast to mammals. Preliminary data, unpublished results, indicate that MsrA protein and transcripts are elevated by anoxia. A recent study on Caenorhabditis elegans demonstrated that FOXO is involved in activation of the MsrA promoter. Using the turtle MsrA promoter sequence we worked to determine which regions in the promoter are necessary for activation by anoxia. The results of the present study were 1) to prepare a TAT-FOXO3a fusion protein which could penetrate animal cells and 2) to construct a FOXO3a expression vector for transcription studies on MsrA expression. / by Diana Navarro. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.
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Hidrocefalia experimental: o Resveratrol apresenta algum benefício como neuroprotetor? / Experimental hydrocephalus: Resveratrol has some benefit as a neuroprotective?Romeiro, Thaís Helena 15 April 2016 (has links)
A hidrocefalia é uma condição neurológica complexa, em que ocorre o desequilíbrio na dinâmica do líquido cefalorraquidiano (LCR) provocando um distúrbio na produção, circulação e reabsorção do mesmo, o que pode levar a uma redução e/ou bloqueio do fluxo sanguíneo. Apesar do tratamento com derivação liquórica ser eficiente na redução da ventriculomegalia, muitos danos neurológicos não são revertidos com a cirurgia. Estudos demonstram que o estresse oxidativo está envolvido na gênese das lesões da hidrocefalia. O objetivo deste trabalho foi avaliar a resposta neuroprotetora do Resveratrol, reconhecido como um potente antioxidante, na hidrocefalia experimental induzida em ratos Wistar jovens. Foram utilizados ratos machos, com sete dias de vida, que receberam uma injeção de caulim a 15% na cisterna magna para indução da hidrocefalia. Esses animais foram divididos em grupo hidrocefálico sem tratamento (n=20), grupo hidrocefálico tratado com Resveratrol através de aplicação de injeção intraperitoneal (20mg/kg/dia) (n=20) e um grupo de animais que não receberam a injeção de caulim para ser usado como controle (n=10). Foram realizadas avaliações comportamentais e estudos de ressonância magnética. Duas semanas após, os animais foram eutanasiados para coleta dos encéfalos, e realizados testes histológicos, imunoistoquímicos e bioquímicos. Os resultados obtidos neste trabalho mostraram que os animais hidrocefálicos, que receberam diariamente injeção de Resveratrol, apresentaram efeito benéfico nos testes comportamentais mostrando mais agilidade e melhor exploração do ambiente, melhor desenvolvimento sensoriomotor, aprendizagem e capacidade de memorização, apresentaram também discreta diminuição da atividade astrocitária evidenciada pela imunomarcação do GFAP no corpo caloso e exibiram aumento significativo na quantidade de antioxidantes totais no plasma. Conclui-se que o uso do Resveratrol diminuiu a atividade astrocitária, aumentou a quantidade de antioxidantes e melhorou a memória e o desenvolvimento motor dos ratos / Hydrocephalus is a neurological condition complex, wherein the imbalance occurs in the dynamics of cerebrospinal fluid (CSF) causing a disturbance in the production, circulation and absorption thereof, which can lead to a reduction and / or blockage of blood flow. Despite treatment with CSF shunt be effective in reducing ventriculomegaly, many neurological damage is not reversed with surgery. Studies have shown that oxidative stress is involved in the genesis of hydrocephalus injuries. The objective of this study was to evaluate the neuroprotective response Resveratrol, recognized as a potent antioxidant in experimentally induced hydrocephalus in young Wistar rats. male rats were used with seven days of life, which received a 15% kaolin injection into the cisterna magna induction of hydrocephalus. These animals were divided into hidrocefálico untreated group (n = 20), hidrocefálico group treated with resveratrol by intraperitoneal injection application (20 mg / kg / day) (n = 20) and a group of animals that received the kaolin injection to be used as control (n = 10). behavioral assessments and magnetic resonance studies were performed. Two weeks later, the animals were euthanized to collect the brains and performed histological, immunohistochemical and biochemical tests. The results of this study showed that hidrocefálicos animals that received daily injection of Resveratrol showed beneficial effect on behavioral tests showing more agility and better exploitation of the environment, better sensorimotor development, learning and memory capacity, also showed a slight decrease of astrocyte activity evidenced by immunostaining of GFAP in the corpus callosum and exhibited a significant increase in the total amount of antioxidants in plasma. We conclude that the use of Resveratrol decreased the astrocyte activity, increased the amount of antioxidants and improved memory and motor development of mice
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Papel da trealose no metabolismo de larvas de Pyrearinus termitilluminas (coleoptera: elateridae) sob estresse hídrico / The role o trehalose in the metabolism of Pyresrinus termitilluminas larvae (coleoptera: elateridae) under hidric stressTorres, Moacir Aluisio 07 November 2003 (has links)
Entre centenas de espécies brasileiras de pirilampos, o Pyrearinus termitilluminans é o único cujo ciclo de vida se passa integralmente nos cupinzeiros luminosos localizados no Brasil central claramente observados durante a estação das chuvas. A emissão de luz nos elaterídeos tem a função de atração de presas para a alimentação. A bioluminescência desses animais desaparece nos meses de seca juntamente com a nuvem de presas aladas. Assim, o metabolismo de trealose aqui estudado poderia prover informações sobre da capacidade da larva de sobreviver em ambientes edáficos. As concentrações de trealose e glicose são determinadas nos extratos de larvas com um sistema DIONEX® de cromatografia iônica. A trealase foi medida com 17 mM de trealose. O glicogênio foi estimado com uma amiloglicosidase. Paralelamente o estresse oxidativo associado com a restrição de água foi monitorado através da determinação do TBARS, juntamente com a catalase, glutationa peroxidase e glutationa redutase. Nas larvas submetidas ao ensaio na câmara climática (25% de umidade) a trealase (159,69±10,95 mU/animal) estava 80 vezes mais alta do que a do grupo controle (2,02±1,41mU/animal). As larvas sob estresse apresentaram distintos níveis de trealose e glicose (29,85±3,20 µmol/animal e 18,27±0,82 µmol/animal, respectivamente) quando comparadas com o grupo controle (64,61±1,54 µmol/animal e 2,16±0,11 µmol/animal, respectivamente). A elevação dos níveis das enzimas antioxidantes (4, 4,3 e 2,4 vezes respectivamente) com níveis invariáveis de TBARS apontam para a ação antioxidante contra a produção elevada de espécies reativas de oxigênio. Os insetos submetidos à restrição hídrica perderam aproximadamente 35% do peso. O aumento da atividade da trealase, com concomitante decréscimo dos níveis de trealose, sugerem que esse açúcar poderia ser usado como fonte hídrica. Entretanto, os níveis de glicose, 10 vezes mais elevados no grupo sob estresse poderia ser usado na via de biossíntese de trealose uma vez que os níveis de glicogênio estão diminuídos. As mudanças no metabolismo de trealose e o desbalanço no equilíbrio redox, poderiam fornecer importantes informações fisiológicas desses insetos sob estresse hídrico. / The life cycle of Pyrearinus termitilluminans (Coleoptera: Elateridae) takes place totally into the so-called luminous termite mounds located in Central Brazil, which are clearly observed during the rainy season. Light emission by the elaterid larvae acts like a trap attracting flying insects. The bioluminescence disappears in the dry months together with the food supply. The trehalose metabolism study described here could provide information about larva capacity to survive throughout hard climatic changes. Trehalose and glucose concentrations are determined in the larva extracts with a DIONEX® ion chromatography system. The trehalase activity was measured with 17 mM trehalose. The glycogen level was estimated with amyloglucosidase. In parallel oxidative stress associated to water deprivation was evaluated through determination of TBARS and the catalase, glutathione peroxidase and glutathione reductase activities. In larvae submitted to dryness in a growth chamber (25% humidity) we have found 80-fold higher trehalase activity (159.69±10.95 mU/animal) than in the control group raised under room conditions (2.02±1.41 mU/animal). Stressed larvae showed distinct trehalose and glucose contents (29.85±3.20 µmol/animal and 18.27±0.82 µmol/animal, respectively) when compared with the control group(64.61±1.54 µmol/animal and 2.16±0.11 µmol/animal, respectively), whereas the glycogen level was lower (11.53±2.01 mg/animal and 28.26±2.31 mg/animal, respectively). Elevation of the antioxidant enzyme levels (4-fold, 4.3-fold and 2.4-fold respectively) with maintenance of TBARS pointed to depletion to exacerbated production of reactive oxygen species. Insects submitted to water restriction lost about 35% wet weight. The observed increase of trehalase activity and concomitant decrease of trehalose level suggest that trehalose could be used as a metabolic water source. Moreover, the 10-fold higher glucose level in the stressed group could be used by the trehalose biosynthetic pathway as the glycogen level decreases in parallel. The trehalose metabolic and redox balance changes described here may shed light on the yet unknown physiological mechanisms of larval elaterid adaptation to water stress.
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Fenil éster do ácido caféico melhora a resposta ao estresse oxidativo em modelo animal de obesidade induzida por dieta hiperlipídica / Caffeic acid of phenethyl ester improves the oxidative stress response in animal model of obesity induced by high fat dietCaetano, Aline Camila 31 August 2010 (has links)
A obesidade é uma doença que vem aumentando de maneira assustadora em todo o mundo e está implicada em várias condições patológicas, como resistência à insulina, diabetes tipo 2, dislipidemia, esteatose hepática, hipertensão e risco de doenças cardiovasculares. Evidências demonstram que a obesidade é um estado de estresse oxidativo crônico que está associado às alterações metabólicas e fisiológicas presentes no organismo humano que incidem no aparecimento das patologias citadas. Para combater o excesso de espécies reativas geradas, os organismos possuem um complexo sistema de defesa que inclui mecanismos enzimáticos e não enzimáticos de desintoxicação. O presente trabalho utilizou camundongos SWISS alimentados com dieta hiperlipídica, modelo experimental de obesidade, tratados com CAPE, composto isolado da própolis descrito como tendo várias atividades biológicas, nas doses de 13 e 30 mg/kg de peso vivo e dois tempos de tratamento, 15 e 22 dias. Neste trabalho, as respostas das enzimas superóxido dismutase (SOD), catalase (CAT), glutationa peroxidase (GSH-Px) e glutationa redutase (GR) foram analisadas nos tecidos hepático e adiposo. Além disso, outros parâmetros importantes foram determinados, como a quantificação da peroxidação lipídica, o conteúdo de peróxido de hidrogênio (H2O2), a atividade da enzima hepática -GT e o controle do ganho de peso, peso relativo do fígado e da gordura (%). Os resultados mostraram que o CAPE não interferiu no ganho de peso dos animais. A dieta hiperlipídica e o tratamento com o CAPE não levaram a alterações significativas nos níveis séricos da enzima hepática, -GT. Os resultados obtidos na resposta ao estresse oxidativo estão de acordo com os encontrados na literatura que têm o CAPE como um potente antioxidante, sendo capaz de melhorar a atividade de algumas enzimas antioxidantes nos tecidos estudados. No tecido hepático, pôde-se observar que a dose de 13 mg/kg de peso vivo foi mais eficiente no combate ao estresse oxidativo induzido pela obesidade, combatendo a produção de peróxido de hidrogênio e, conseqüente, peroxidação lipídica. Já no tecido adiposo, a dose de 30 mg/kg de peso vivo melhorou a atividade da GSH-Px, mas não afetou de forma significativa a atividade das outras enzimas avaliadas. Com isso, podese sugerir que o CAPE na dose de 13 mg/kg de peso vivo por 15 dias e a dose de 30 mg/kg de peso vivo por 22 dias melhora a resposta ao estresse oxidativo induzido pela obesidade nos tecidos hepático e adiposo, respectivamente. / Obesity is a disease that is increasing in a drastically way around the world and is implicated in many pathological conditions, such as insulin resistance, type 2 diabetes, dyslipidemia, fatty liver disease, hypertension and cardiovascular risk. Evidence has shown that obesity is a chronic oxidative stress state that is associated with metabolic and physiological changes present in human organism that emerge pathologies mentioned. To prevent excessive reactive oxygen species (ROS) generated, the organisms have a complex system of defense mechanisms including enzymatic and non-enzymatic detoxification. The present study utilized SWISS mice fed with high fat (HF) diet, an experimental model of obesity, treated with CAPE, an isolated compound from propolis that present many biological activities, at doses of 13 and 30 mg / kg body weight and two treatment times, 15 and 22 days. In this study, the responses of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were analyzed in liver and adipose tissues. In addition, other important parameters were performed, such as lipid peroxidation, hydrogen peroxide (H2O2) content, liver enzyme activity ?-GT and the weight gain, relative weight of liver and adipose tissue (%). The results showed that CAPE did not interfere with the daily weight gain of animals. The high fat diet and treatment with CAPE did not lead to significant changes in serum liver enzyme ?-GT. The results obtained in response to oxidative stress are in agreement with the literature that have CAPE as a potent antioxidant, being able to improve the activity of some antioxidant enzymes in the tissues studied. In liver, it was observed that the dose of 13 mg / kg body weight was more effective preventing oxidative stress induced by obesity, the production of hydrogen peroxide and, consequently, lipid peroxidation. In adipose tissue, the dose of 30 mg / kg body weight improved the activity of GSH-Px, but did not affect significantly the activity of other enzymes evaluated. Thus, we can suggest that CAPE at a dose of 13 mg / kg body weight for 15 days and 30 mg / kg body weight for 22 days improves the response to oxidative stress induced by obesity in the liver and adipose tissue, respectively
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