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Hepatic Steatosis and TNF-?? SignalingModi, Nita January 2007 (has links)
The overall objective of this research was to investigate the status of tumor necrosis factor-?? (TNF-??), and molecules associated with its signaling, in the pathological state of hepatic steatosis. The effect of NSAID piroxicam, a cancer preventive agent also known to affect TNF-?? signaling on hepatic steatosis, was also investigated. The biological state of the tissue was assessed by examining the expression of TNF-?? signaling molecule in whole tissue, as well as in hepatic lipid raft. Lipid rafts are dynamic assemblies of cholesterol and sphingolipids, microdomains that form in the exoplasmic leaflet of the biological membranes shown to play a role in compartmentalization, modulation and integration of the cell signaling.
In the present research, Zucker obese rats were used as a model of human obesity and insulin resistant state. These rats exhibit hepatic steatosis in adulthood similar to those noted in obese individuals. Female Zucker obese and lean rats (5 weeks old) were fed a semisynthetic diet with or without piroxicam (150 ppm). Zucker lean counterparts served as control. After 8 weeks of feeding, rats were euthanized and liver from each animal was collected. Liver tissue from each animal was processed for histology and biochemical analysis which included lipids and proteins (COX-1 and 2, TNF-??, TNF-RI and RII, IKK-??, I??B-?? and NF-??B). Liver histology and the level of total lipids confirmed that Zucker obese rats had hepatic steatosis, which was further augmented by piroxicam treatment. Whole tissue protein expression, using western blot, showed that the steatotic liver differed from non-steatotic livers by having lower levels of TNF-RII. TNF-RII showed a trend which was inversely proportional to the pathological state of the tissue. The obese-piroxicam liver had the lowest level of TNF-RII and lean livers had the highest (p<0.05). The total NF-??B level was higher in the obese and obese-piroxicam groups compared to the lean or lean-piroxicam groups (p<0.05). Piroxicam treatment lowered the level of NF-??B in obese and lean livers. I??B-?? was higher in obese livers than in lean livers. The nuclear level of NF-??B by western blot analysis showed the same pattern as noted in the whole tissue homogenate. However, the difference in the level between obese and lean was marked. The obese nuclei contained two to three fold higher levels of NF-??B protein than the lean liver nuclei. I??B-?? level was significantly higher in the obese liver tissues and nuclei than their lean counterparts. While transcriptionally active NF-??B was higher (p<0.05) in the obese livers than in the lean livers, the difference between obese and lean groups was not as significant as that noted for the level of NF-??B assessed by western blot. This suggests that the proportion of active NF-??B present in the nuclear fraction is much higher in the lean than in the obese nuclei.
Lipid raft was extracted and identified successfully from obese and lean livers. The total caveolin and flotillin levels were significantly higher in the liver lipid rafts of the obese-piroxicam than that of the other groups. This is the group that also exhibited higher steatosis. Piroxicam treatment significantly decreased the level of caveolin in the lean liver and significantly increased the level of flotillin in the obese liver. While COX-1 was not detectable, however, the level of COX-2 and TNF-RII in lipid raft was opposite to the level noted in the whole tissue homogenate. TNFRII was highest in the obese-piroxicam lipid raft and lowest in the lean-piroxicam lipid raft. TNF-RII, COX-2, I??B-?? and NF-??B proteins were the molecules profoundly affected by the pathological state of the tissue and piroxicam treatment. This research is the first to report the presence of I??B-?? in the nuclear compartment with a higher level in the nuclei and whole tissue in the obese liver than in the lean liver. This research demonstrates that TNF-?? to NF-??B axis is altered in steatotic liver, and analysis of lipid rafts in steatotic and non-steatotic liver demonstrates that lipid rafts play a distinct role in modifying the biological availability of key proteins in the pathological state of liver steatosis.
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Les mécanismes de réponse à l'inflammation chronique dans le foie stéatosique et les conséquences sur l'homéostasie cellulaire et la cancérogénèse / Response mechanisms to chronic inflammation in steatotic liver and consequences on cellular homeostasy and carcinogenesisDegli Esposti, Davide 15 June 2011 (has links)
Le foie est un organe essentiel à la vie chez tous les mammifères. C’est un organe central du métabolisme énergétique et de la détoxification des substances xénobiotiques auxquelles l’individu est exposé. Le foie est la cible d’agressions diverses, telles que les virus, l’alcool, les substances chimiques présentes dans l’alimentation ou l’environnement. Il peut également subir destransformations pathologiques profondes, lors du diabète ou de l’obésité par exemple.La stéatose hépatique, caractérisée par une accumulation de triglycérides sous forme de vésiculesgénérant une réponse inflammatoire, est connue depuis de nombreuses années. Son étude a permisde définir un modèle en deux étapes (« two hits ») indispensables à la genèse d’une stéatohépatite ou NASH. La première est l’accumulation de lipides, la seconde consiste en la genèse d’un stress oxydant et la libération de cytokines. La NASH est une des conséquences pathologiques du syndrome métabolique au cours duquel une résistance des tissus à l’insuline se développe.Récemment, la composition des lipides accumulés dans la NASH a été décrite et montre la présence de cholestérol libre et de différents métabolites des acides gras dont la toxicité est grande mais variable. De façon surprenante, une nouvelle hypothèse tend à émerger quant aux rôles protecteurs de certaines catégories de lipides. En effet, le stockage des triglycérides sous forme de vésicules pourrait être un mécanisme de survie cellulaire (Neuschwander-Tetri, 2010). Il s’agirait principalement d’une tolérance à la mort cellulaire par nécrose ou apoptose. Dans ce contexte,l’activation de l’autophagie serait capitale et la nécrose ne serait plus un mécanisme non contrôlé,mais au contraire un système finement régulé.Des données expérimentales récentes suggèrent l’existence d’un réseau complexe d’interactions moléculaires qui lient, dans la NASH comme dans le cas de la cancérogenèse, le métabolisme énergétique, la réponse inflammatoire systémique et tissulaire et des altérations subcellulaires, telles que les lésions des mitochondries et du réticulum endoplasmique.Nous avons utilisé le cas particulier du préconditionnement ischémique, une technique chirurgicale qui consiste, grâce à de courtes périodes d’occlusion vasculaire avant l’ischémie, à conférer au tissu une protection contre les lésions d’ischémie/reperfusion (I/R), pour étudier les mécanismes de survie mis en place par les hépatocytes stéatosiques au cours d’un stress d’I/R. Dans deux contextes différents, celui d’une ischémie chaude au cours d’une hépatectomie partielle et celui d’une ischémie froide au cours de la transplantation hépatique, nous avons montré que l’autophagie peut jouer un rôle central dans la protection des hépatocytes stéatosiques. Cependant, il est envisageable qu’un dysfonctionnement de l’autophagie pourrait conduire à la genèse d’altérations cellulaires comme une instabilité génomique, caractéristique de la transformation cancéreuse. L’équilibre entre la survie et la mort cellulaire dépend donc de l’intégration de cette signalisation complexe, qui concerne l’état énergétique de la cellule, la réponse aux stress transitoires et l’adaptation aux stress chroniques. Dans ce contexte, l’autophagie semble jouer un rôle central dans l’intégration de la réponse aux stress (Kroemer et al 2010), ce qui pourrait favoriser directement ou indirectement la transformation cancéreuse d’une cellule.L’amélioration de la compréhension des mécanismes impliqués dans la tolérance et la survie des hépatocytes chargés de lipides en réponse à un stress inflammatoire, ischémique ou du réticulum endoplasmique semble donc essentielle. Elle permettrait en effet la mise en place de nouvelles stratégies thérapeutiques qui pourraient améliorer la prise en charge des patients, augmenter le nombre de greffons disponibles pour les greffes, et la prévention des risques cancérogènes pour le foie. / Liver is a an essential to life organ in all mammals. It plays a central role in energy and drug metabolism. Liver is constantly challenged by damaging compounds such as viruses, alcohol and chemicals from food intake or from the environment. It can also undergo some deep pathological transformations, e.g. in diabetes or obesity. Liver steatosis has been known for many years, it is defined as an accumulation of triglycerides vesicles generating an inflammatory response in hepatocytes. A « two step hypothesis » has been proposed for the genesis of Non Alcoholic Steatohepatitis (NASH). The first step is the fat accumulation, the second step involves the generation of an oxidative stress and the release ofcytokines. NASH is one of the pathological consequences of metabolic syndrome, when insulin resistance occurs in the tissues.The composition of accumulated fat in NASH has been recently described and reveals the presence of free cholesterol and different fatty acids metabolites with a high but variable toxicity. Surprisingly, a new hypothesis tends to emerge about the protective effects of some types of lipides.Triglyceride storage in vesicles could indeed be a survival mechanism for cells (Neuschwander-Tetri, 2010). It is assumed that it would mainly result in an tolerance to cell death by necrosis orapoptosis. In this context, (activation of) autophagy would play a key-role and necrosis, usually an uncontrolled mechanism, would become accurately regulated. Similarly to oncogenesis, recent experimental data in NASH suggest that energy metabolism,systemic and tissular inflammatory response and subcellular alterations such as impaired mitochondria and ER are connected in a complex network of molecular interactions. Ischemic preconditioning (IP) is a surgical technique consisting of brief periods of vascular occlusion which confer protection against subsequent ischemia/reperfusion via endogenous protective mechanisms. We investigated the survival mechanisms set up by steatotic hepatocytes during I/R, with or without IP. In the following two situations, warm ischemia during partial hepatectomy and cold ischemia during liver transplantation, we pointed out that autophagy can play a central role in steatotic hepatocytes protection. However, an autophagy dysfunction might result in the generation of cellular impairments such as genomic instabilities, typical features of oncogenic transformation. Therefore, the balance between cell survival or death depends on the integration of a complex signaling, taking into account the cellular energetic state, the cell response to transient stress and its adaptation to chronical stress. In that context, autophagy seems to play a central role in the integration of stress response (Kroemer et al Mol Cell 2010), which could promote, directly or indirectly the malignant cell transformation.Therefore, it seems essential to improve the understanding of mechanisms involved in tolerance and survival of lipid-full hepatocytes in response to an inflammatory, ischemic or ER stress. Indeed, this would help developing new therapeutical strategies to improve patients care, increase the number of available grafts for transplants, and prevent cancer risks in liver.
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The Effects of Cyp2e1 on Hepatic Gene Expression in 129/Sv-Cyp2e1^tm1Gonz/J and 129S1/SvImJ Mice Exposed to HydrazineLindgren, Kristjon, Seng, Dana January 2007 (has links)
Class of 2007 Abstract / Objectives: To characterize the difference in hepatic gene expression between Cyp2e1 +/+ and Cyp2e1 -/- mice after exposure to hydrazine in order to elucidate the functional pathway(s) for hydrazine-induced steatosis.
Methods: The project was designed by Dr. Charlene McQueen and consisted of the following aims: (1) to characterize the hepatic pathology induced by hydrazine in CYP2E1 +/+ and -/- mice, (2) to evaluate hepatic gene expression profiles following exposure to hydrazine, and (3) to determine the expression of CYP2E1 and CYP4A14. The animal exposure and data collection have been completed and aim #2 is awaiting data analysis.
Aim #2 consisted of treating CYP2E1 +/+ and CYP2E1 -/- mice to saline and hydrazine at doses of 100 mg/kg. Livers were collected at six and 24 hours and the mRNA was isolated with an Absolutely RNA RT-PCR Miniprep Kit. The transcriptome was determined using the Affymetrix GeneChip Expression Analysis System using total mouse genome GeneChips. The GeneChips were scanned using an Agilent GeneArray Scanner and the image was quantitated and archived awaiting data analysis.
The data was collected by the SWEHSC Microarray Facility on June 20, 2005 was analyzed. The data analysis was completed by both Kristjon Lindgren and Dana Seng with the help and training from Dr. George Watts. The six sets of data from aim #2 was analyzed using Agilent's GeneSpring 7.3.1 software to characterize the two-fold differences in mice (n = 2 per group) hepatic gene expression. Genes of interest were identified as containing the keywords cyp, fatty, glutathione, hepat, lipid, liver, oxid, perox, steroid, and phosphatidylinositol in the Gene Ontology Biological Process, Cellular Component, or Molecular Function descriptions. Lastly, pathway mining of/for genes of interest was performed using Bioresource for array of genes (BioRag) available at www.biorag.org and maintained by the AzCC/SWEHSC Bioinformatics Facility.
Results: The amount of information extracted from this research project is too immense to be described or summarized on this form. For more information, please obtain a copy of this research project from the University of Arizona College of Pharmacy or from the project co-authors Kristjon Lindgren (kristjon.lindgren@gmail.com) or Dana Seng (dana.seng@gmail.com).
Conclusions: The effects of Cyp2e1 on hepatic gene expression in 129/Sv-Cyp2e1tm1Gonz/J and 129S1/SvImJ mice exposed to hydrazine was analyzed. Data showing that Cyp2e1 was protective against HD-induced hepatotoxicity was consistent with the proposed hypothesis. Hepatic gene expression results show that Cyp2e1 -/- mice have decreased expression of microsomal ω-oxidation genes (Cyp4a10 and Cyp4a14) compared to Cyp2e1 +/+ at 6h (both increased at 24h) and peroxisomal β–oxidation genes (Ehhadh) at 6h like Cyp2e1 +/+ (but increased at 24h only in Cyp2e1 -/-). Conversely, an increased expression of mitochondrial β-oxidation genes (Cpt1a) in both genotypes at 6 and 24h and cholesterol synthesis genes (Fdft1, Hmgcr, Hmgcs1, Idi, Lss, Mvk, Nsdhl, Sc4mol, and Sqle) in Cyp2e1 -/- at 24h was observed. These results support mechanisms by which ω-oxidation or PPARγ is protective or peroxisomal β- oxidation is damaging. Additional studies are needed to further eludidate the mechanisms of HD-induced steatosis.
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Transgenic Overexpression of Ctrp3 Prevents Alcohol-Induced Hepatic Triglyceride AccumulationTrogen, Greta, Bacon, Joshua, Li, Ying, Wright, Gary L., Degroat, Ashley, Hagood, Kendra L., Warren, Zachary, Forsman, Allan, Kilaru, Aruna, Clark, W. Andrew, Peterson, Jonathan M. 15 May 2018 (has links)
This study tested the ability of a novel adipose tissue derived cytokine, C1q TNF-related protein-3 (CTRP3), to prevent alcohol-induced hepatic lipid accumulation, or alcoholic fatty liver disease (ALD). Previous work has demonstrated that CTRP3 is effective at preventing high-fat diet-induced fatty liver; however, the potential of CTRP3 to inhibit ALD has not been explored. To test the potential protective effects of CTRP3, transgenic mice overexpressing CTRP3 (Tg) or wild-type littermates (WT) were subjected to one of two different models of ALD. In the first model, known as the NIAAA model, mice were fed control or alcohol-containing liquid diets (5% vol/vol) for 10 days followed by a single gavage of ethanol (5 g/kg). In the second model, the chronic model, mice were fed control or alcohol-containing diets for 6 wk with no gavage. This study found that CTRP3 reduced triglyceride accumulation in the chronic model of alcohol consumption by ~50%, whereas no reduction was observed in the NIAAA model. Further analysis of isolated primary hepatocytes from WT and Tg mice demonstrated that CTRP3 increased oxygen consumption in the presence of fatty acids, indicating that CTRP3 increases hepatic fatty acid utilization. In conclusion, this study indicates that CTRP3 attenuates hepatic triglyceride accumulation in response to long-term chronic, but not short-term, alcohol consumption.
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The effects of plant versus marine sources of dietary omega-3 fatty acids on hepatic steatosis and adipose function in fa/fa Zucker ratsHong, Lena 01 April 2015 (has links)
Non-alcoholic fatty liver disease (NAFLD) is a common consequence of metabolic syndrome (MetS) with the least severe form of NAFLD being hepatic steatosis, which is the accumulation of intrahepatic fat. Omega-3 polyunsaturated fatty acids (n3 PUFAs) are fatty acids in our diets commonly found in marine animals (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and certain plants (α-linoleic acid [ALA]). Although past studies have examined the consumption of marine sources or plant sources on hepatic steatosis and MetS parameters, individual n3 PUFA have yet to be compared to each other. Thus fa/fa Zucker rats were provided n3 PUFA diets containing ALA, EPA or DHA for 8 weeks relative to a linoleic acid (LA)-rich n6 PUFA diet provided to fa/fa and lean Zucker rats. Comparisons were to baseline fa/fa Zucker rats. It was shown that DHA prevented the progression of hepatic steatosis and was associated with improvements in insulin resistance.
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MicroRNA-33 regulates sterol regulatory element-binding protein 1 expression in mice / マイクロRNA-33は生体内でSREBP-1の発現を制御するNishino, Tomohiro 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19600号 / 医博第4107号 / 新制||医||1014(附属図書館) / 32636 / 京都大学大学院医学研究科医学専攻 / (主査)教授 萩原 正敏, 教授 清水 章, 教授 川上 浩司, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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Elucidating the Role of Biliary Senescence and Mast Cell-Mediated Therapy in Non-Alcoholic Fatty Liver DiseaseKundu, Debjyoti 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Non-alcoholic fatty liver disease, or NAFLD, is characterized by excess fat deposition in the liver. Cellular senescence is a critical hallmark of NAFLD. Cholangiocytes in the liver plays a significant role in the progression of fatty liver by contributing to senescence. p16 is the main senescent protein expressed by cholangiocytes in primary sclerosing cholangitis (PSC). Thus, we aimed to downregulate p16 by vivo-morpholino and evaluate the disease phenotypes and signaling mechanisms in a murine model of NAFLD. We found that downregulation of p16 reduced i) steatosis), ii) inflammation, iii) fibrosis, and cholangiocyte proliferation in HFD mice compared to the HFD-fed, control vivo-morpholino injected mice.
Moreover, the downregulation of p16 reduced insulin-like growth factor-1 (IGF-1) in cholangiocytes, previously identified by our laboratory as a principal SASP factor secreted from cholangiocytes during NAFLD. By ingenuity pathway analysis, we found that p16 might regulates IGF-1 expression via the E2F1/FOXO1axis. Further analyses indicate that p16 downregulation reduces E2F1 mRNA transcription, inhibiting FOXO1 and subsequent IGF-1 expression in cholangiocytes.
The presence of mast cells in the liver has been implicated in multiple cholangiopathies. Our lab demonstrated that mast cell stabilization by cromolyn sodium treatment reduced histamine secretion, fibrosis, and biliary proliferation in Mdr2-/- mice, a model of PSC. Thus, we aimed to determine mast cell stabilization as a therapeutic approach to managing NAFLD and its more advanced form, NASH. We found that cromolyn sodium ameliorated i) serum histamine levels, ii) intrahepatic mast cells, iii) inflammation, iv) fibrosis, v) steatosis, and cholangiocyte proliferation in methionine choline deficient diet-fed mice compared to the saline controls. Overall, we report that amelioration of senescence is a critical factor in improving the disease phenotypes in NAFLD. Biliary senescence plays a crucial role in modulating the disease progression in NAFLD, and mast cell stabilization can be used as a therapeutic approach to reduce pathological hallmarks of fatty liver. / 2024-05-22
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Deletions of Fstl3 and/or Fst Isoforms 303 and 315 Results in Hepatic SteatosisUngerleider, Nathan A 01 January 2010 (has links) (PDF)
TGFβ ligands, activin and myostatin have been shown to stimulate insulin production and secretion. Antagonists, Follistatin (FST) and Follistatin like 3 (FSTL3) were partially and fully ablated, respectively, creating hyperinsulinemic mice with fatty liver. Much research has surfaced on the connection between hepatic steatosis and hepatic insulin resistance. We present two different models, each with a different mechanism behind the development of fatty liver. FST288-only mice have increased synthesis of mRNA and proteins responsible for hepatic triglyceride (TG) uptake, while our double mutants have increased synthesis of mRNA and proteins responsible for TG synthesis. This alteration was likely independent of hepatic insulin resistance as livers from both mouse lines were insulin sensitive. Experiments conducted in this study to realize the causal factor of hepatic steatosis can be performed on adipose and muscle tissues in the future to better characterize the phenotype.
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Anatomia das vias sanguíneas e biliares e histologia do fígado de Avestruz (Struthio camelus, Linnaeus, 1758) / Anatomy and histology of the blood-vessels and biliar duct system of ostrich liver (Struthio camelus Linnaeus, 1758)Saviani, Gisele 02 July 2009 (has links)
Hoje a criação de avestruz ((Struthio camelus, Linnaeus 1758)) é uma atividade de grande potencial, porém não existem padrões definidos sobre a histologia do seu fígado, que é um órgão de grande importância no metabolismo, o conhecimento de sua histologia e anatomia pode contribuir para a detecção de doenças e deficiências nutricionais que influenciam no crescimento e desenvolvimento do animal. Os objetivos desta pesquisa são: Estudar a anatomia e histologia do fígado e a ramificação de sua artéria hepática, veia porta hepática e ducto biliar. Para a realização da parte macroscópica foram utilizados quinze avestruzes com idades entre 12 e 18 meses (com peso médio em torno de 80 a 100 kg), provenientes do abatedouro Don Pig, situado próximo à cidade de Botucatu no estado de São Paulo. Os animais foram abatidos com pistola pneumática e posteriormente submetidos a sangria. Foram injetadas com látex a artéria hepática, o ducto biliar e a veia porta. O fígado dos avestruzes apresentam dois lobos (direito e esquerdo). No caso o direito é maior que o esquerdo e ambos são subdivididos em dorsal, intermédio e ventral. Além disso, amostras do fígado foram processadas para a observação em microscopia de luz e microscopia eletrônica de transmissão (MET). A hematoxilina e eosina (H.E), picrossírius, Gordon e Sweets, Sudan black e o ácido peródico de Schiff (PAS) são colorações usadas respectivamente para observar a morfologia do fígado, colágeno, fibras reticulares, gordura e glicogênio. Foram encontrados os espaços porta- hepáticos (artéria hepática, veia porta e ducto biliar e as veias centrolobulares). O glicogênio presente mostrou a média de 5,68%. O conteúdo lipídico, conferiu um aspecto goticular compatível com um quadro de esteatose hepática e a média obtida foi de 9,83%. Foi encontrado colágeno ao redor dos espaços porta-hepáticos, artérias centrolobulares e capilares sinusóides e a média foi de 14,71%. Encontrou-se também fibras reticulares ao redor dos capilares sinusóides e a média foi de 5,96%. Quanto à MET notou-se que no citoplasma dos hepatócitos desses animais existem numerosas mitocôndrias, glicogênio, muitas gotas de gordura, alguns lisossomos, retículo endoplasmático granular ao redor das mitocôndrias, algumas células estreladas, eritrócitos, núcleo, célula em degeneração e o canalículo biliar ao centro. Provavelmente o quadro sugestivo de esteatose é resultante do estado nutricional dos animais, já que nenhum outro aspecto relevante foi encontrado. Como estas aves são destinadas ao abate, sua alimentação é formulada para que os animais apresentem rápido desenvolvimento e alto ganho de peso, provavelmente com níveis de lipídios acima do necessário, causando uma deposição de micelas de gordura nos hepatócitos. Estes resultados demontraram que os hepatócitos dos avestruzes são muito simulares as outras aves apesar de também serem muito similares na estrutura das células do fígado de mamíferos. / At present the ostrich (Struthio camelus) breeding has been showing a great economical potential, although yet there are not distinct patterns about the histology of its liver, which is an organ of key importance in terms of metabolism. The knowledge of its histology and anatomy can help the detection of diseases and nutritional deficiencies that affect the growth and development of this bird. The aims of this work are to study the liver anatomical and histological structure and the branching of the hepatic artery, hepatic portal vein and bile duct. In the macroscopic study 15 ostriches with an average age of 12-18 months and average weight of 80-100 Kg, proceeding from Don Pig Abatteur, located next to Botucatu, São Paulo, were used. The birds were slaughtered with air gun and subsequently submitted to bleeding. The hepatic artery, the bile duct and the hepatic portal vein were injected with latex. The ostrich liver presents two lobules (right and left), being the right one larger than the left and both are subdivided into dorsal, intermediate and ventral. Liver samples were processed for light and electron transmission microscopic studies. Hematoxilin and eosin (HE), picrosirius, Gordon and Sweets, Sudan black and Schiff periodic acid (PAS) were respectively used to observe the liver morphology, collagen, reticular fibers, lipids and glycogen. The liver portal spaces were determined (hepatic artery, portal vein, bile duct and centrolobular veins). An average of 5.68% of glycogen was observed. The lipidic content provided a droplet aspect compatible to hepatic esteatosis, with an average of 9.83%. Collagen fibers around the liver portal spaces, centrolobular arteries and sinusoidal cappilaries were detected, at an average of 14.71%, as well as reticular fibers located in the vicinity of sinusoidal capillaries with an average of 5.96%. Through transmission electron microscopy we noticed in the hepaticyte cytoplasm the presence of numerous mithocondria, glycogen, several lipidic droplets, some lysosomes, granular endoplasmatic reticulum around the mithocondria, some stellate cells, erythrocytes, nucleus and degenerating cells, besides the central biliary canaliculus. The suggestive steatotic results might result from the animals nutritional status, once no other relevant aspect was detected. The birds are slaughtered for food comsumption and their ration is balanced striving for faster growth and higher weight gains, which are achieved through extra lipidic levels, motivating deposition of lipidic micelles in the hepatocytes. Our results demonstrated that ostrich and other birds hepatocytes are very similar.
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Efeito do consumo de tremoço (Lupinus albus) e seu isolado protéico no metabolismo do colesterol em hamsters hipercolesterolemizadosFontanari, Gustavo Guadagnucci [UNESP] 18 June 2010 (has links) (PDF)
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fontanari_gg_dr_arafcf.pdf: 3134034 bytes, checksum: cedb3c38cb79d12942589999bc81fb5a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A soja e outras leguminosas são consideradas alimentos funcionais por apresentarem propriedades hipocolesterolemizantes. Esta propriedade, porém, ainda não foi elucidada para o tremoço e seus isolados protéicos. Um possível componente deste grão responsável pelo efeito redutor de colesterol é sua proteína. Objetivo: Produzir isolado protéico de tremoço e verificar a influência do grão integral e de seus isolados protéicos no metabolismo do colesterol de hamsters hipercolesterolemizados pela dieta. Métodos: O isolado protéico (IP) de tremoço foi produzido por precipitação isoelétrica, utilizando-se pH 10,0 para solubilização da proteína e pH 5,0 para sua precipitação, obtendo-se um isolado protéico de 92,41% de proteína. O IP e a farinha de tremoço integral (FI) foram usados como fonte protéica em dietas experimentais para hamsters que tiveram hipercolesterolemia induzida por dieta contendo 13,5% de gordura saturada e 0,1% de colesterol, por 21 dias. Os animais foram divididos em 3 grupos, recebendo cada grupo dieta com 20% de caseína (controle), dieta com 20% de proteína respectiva do IP e dieta com 20% de proteína respectiva da farinha integral de tremoço (FI), por 28 dias. Resultados: Comparando-se a dieta controle (HC), as dietas IP e FI provocaram reduções significativas no colesterol total (15,3 e 16,88%, respectivamente) e colesterol não-HDL (28,6 e 43,41%, respectivamente). Análises histológicas do fígado foram realizadas e observou-se que o IP e o FI apresentaram efeito hepatoprotetor comparado à HC, que apresentou esteatose difusa e intensa (nível 4+), enquanto que os grupos tremoço integral e isolado protéico apresentaram esteatose focal (nível 1). Alguns possíveis mecanismos envolvidos para o efeito benéfico no metabolismo lipídico foram investigados. A excreção... / Soya and other legume seeds are considered functional food because of their hypocholesterolemic properties. However this property was still not elucidated for lupine and its protein isolates. A possible component of this grain responsible for the redactor effect of cholesterol is its protein. Objective: Produce lupine isolate and verify the influence of the whole grain and its protein isolate on cholesterol metabolism in diet hipercholesterolemized. Methods: The lupin protein isolate (PI) was produced by isoelectric precipitation, using pH 10.0 for solubilization of the protein and pH 5.0 to its precipitation, obtaining a protein isolate of 92.41% of protein. The PI and lupine flour whole (FW) were used as source of protein in experimental diets for hamsters that had hipercholesterolemia induced by a 21 days diet containing 13.5% of saturated fat and 0.1% of cholesterol. The animals were divided into 3 groups, receiving each group a 28 days diet with 20% of casein (Control), diet with 20% of protein of protein isolate of lupine (PI) and diet with 20% of protein from lupine whole flour (WF). Results: Comparing the control diet (HC), the diets PI and WF caused significant reductions in total cholesterol (15.3 and 16.88%, respectively) and cholesterol not-HDL (28.6 and 43.41%, respectively). Histological analysis of liver were accomplished and noticed that the PI and the WF presented hepatoprotector effect compared to HC, which presented diffuse and intense steatosis (level 4+), while the groups whole lupine and protein isolate, presented focal steatosis (level 1). Some possible mechanisms for the beneficial effects in lipid metabolism were investigated. The excretion of fecal cholesterol was inversely proportional to the plasmatic levels of the animals cholesterol submitted to the different diets. The animals with the WF diet... (Complete abstract click electronic access below)
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